Vertical centrifuge and method for separating water-soluble substances and components using a vertical centrifuge

Abstract

To provide a vertical centrifuge using ribs on a guide cylinder and a method for separating water-soluble substances and components in a raw liquid, which can remove water-soluble substances and components in the raw liquid from clean oil (light liquid side) using a vertical centrifuge and transfer them to the seal water side. [Solution] A vertical centrifuge (1) introduces the raw liquid, which is the liquid to be treated, into a treatment chamber equipped with a plurality of separation plates (17) on the outer periphery of a guide tube (15), and obtains a clean liquid on the light liquid side. The vertical centrifuge (1) is characterized in that a plurality of ribs (15A) are provided at the bottom of the guide tube (15) that extend radially to the outer periphery of the inner surface of the skirt portion, which expands conically, and when the raw liquid is positioned in a direction toward the circumferential edge of the lower part of the skirt portion, the ribs (15A) add centrifugal force to the increased pushing force, which pushes the seal water present around the skirt portion. The pushed-in seal water generates a restoring force in the pushing direction due to the centrifugal force, and the pushing force of the raw liquid and the restoring force generated by the seal water collide, forming a turbulent flow at the boundary between the raw liquid and the seal water.

Description

[Technical Field]

[0001] The present invention relates to a vertical centrifuge and a method for separating water-soluble substances and components using the vertical centrifuge, and more particularly to a vertical centrifuge and a method for separating water-soluble substances and components using the vertical centrifuge, which are capable of transferring water-soluble substances and components in an undiluted liquid to a separated water side (heavy liquid side) or a sludge side by the action of ribs for enhancing the extrusion force formed on the inner surface of a guide cylinder. [Background technology]

[0002] Carbon-neutral fuels are attracting attention in aircraft, ships, automobiles, and other applications in light of global warming. Carbon-neutral fuel is a fuel in which the amount of greenhouse gases (GHG) emitted and absorbed is in balance. In other words, the amount of greenhouse gases emitted, such as carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons, is absorbed or removed somewhere, resulting in a net zero amount of greenhouse gas emissions.

[0003] In recent carbon-neutral fuels, offshore structures, and land facilities, it has been pointed out that raw solutions containing water-soluble substances and components such as ammonia, sodium (Na), and potassium (K) may affect downstream equipment in oil purifiers, making it desirable to remove them using oil purifiers.

[0004] When ammonia fuel is used as a carbon-neutral fuel in engines, ammonia may get mixed into the lubricating oil used in the engine. If this lubricating oil is reused, the ammonia that has gotten into the lubricating oil may have a negative effect on the equipment.

[0005] Furthermore, ships equipped with gas turbines may use diesel fuel as fuel for the gas turbines. Since diesel fuel cannot be produced on board the ship, it is transported by sea to the ship. During marine transportation, there is a risk that alkali metals such as sodium and potassium may become mixed into diesel fuel. These alkali metals may generate corrosive substances inside gas turbine equipment, so they must be removed from the diesel fuel. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 61-35861 Summary of the Invention [Problem to be solved by the invention]

[0007] In the centrifugal separator of Patent Document 1, ribs are provided on the distributor to guide the flow of the product (raw liquid) from the opening to the ascending passage. The flow of the product supplied through the opening is guided to the ascending passage through the ribs. The ribs ensure the flow from the opening to the ascending passage.

[0008] According to the centrifuge of Patent Document 1, the ribs provided on the inner surface of the distributor extend to an opening for directing the raw liquid into an ascending flow path provided in the dish, and the raw liquid is guided to the ribs in the ascending flow path, so that separation of the liquid phase of the raw liquid and centrifugation of the solid matter can be performed in a single centrifugal drum.

[0009] However, it was found that the water-soluble substances and ammonia, a component of the raw liquid, did not transfer completely to the heavy liquid, separating water (sealing water), in the guide tube, and although the heavy liquid (water) could be separated from the raw liquid, ammonia did not separate, resulting in ammonia being contained in the light liquid. It was also found that similar problems existed with water-soluble substances and alkali metals such as sodium (Na) and potassium (K) contained in the raw solution.

[0010] Centrifugal separators are used as oil purifiers to remove solids and water from the raw liquid. However, the water-soluble substances and components contained in the raw liquid originate from the manufacturing process and transportation of the raw liquid, making them difficult to remove.

[0011] Therefore, an object of the present invention is to provide a vertical centrifuge using ribs on a guide cylinder and a method for separating water-soluble substances and components in a raw liquid using a vertical centrifuge, which can remove water-soluble substances and components in the raw liquid from the clean oil (light liquid side) and transfer them to the seal water side.

[0012] Further objects of the present invention will become apparent from the following description. [Means for solving the problem]

[0013] The above problems are solved by the following inventions.

[0014] 1. A vertical centrifuge in which a raw liquid to be treated is introduced into a treatment chamber having a plurality of separation plates on the outer periphery of a guide cylinder, and a clean liquid is obtained on the light liquid side, a plurality of ribs extending radially to an outer periphery of an inner surface of a skirt portion expanding conically at a lower portion of the guide tube; When the concentrate is positioned in a direction toward the circumferential edge of the lower part of the skirt portion, the rib is added to the centrifugal force and the enhanced pushing force pushes in the sealing water present around the skirt portion, The pressed-in seal water generates a restoring force in the pushing back direction due to centrifugal force, A vertical centrifugal separator characterized in that the pushing force of the raw liquid and the restoring force generated by the seal water collide to form a turbulent flow at the boundary surface between the raw liquid and the seal water. 2. 2. The vertical centrifuge according to claim 1, wherein the rib is detachably provided on the inner surface of the skirt portion. 3. 2. The vertical centrifuge according to item 1, wherein the formation of the turbulent flow extracts water-soluble substances and components from the liquid to be treated and transfers them to the sealed water side. 4. 4. The vertical centrifuge according to item 3 above, wherein the water-soluble substance and component include ammonia. 5. 3. The vertical centrifuge according to item 3, characterized in that it contains the water-soluble substance and an alkali metal component. 6. 2. The vertical centrifuge according to claim 1, wherein the rib extends to the inside of the guide cylinder. 7. 2. The vertical centrifuge according to item 1, wherein a plurality of semicircular notches are formed at predetermined intervals on the outer periphery of the skirt portion. 8. A method for separating water-soluble substances and components using a vertical centrifuge, in which a raw liquid to be treated containing water-soluble substances and components is introduced into a treatment chamber equipped with a plurality of separation plates on the outer periphery of a guide cylinder, and a light liquid from which the water-soluble substances and components have been treated is extracted, a skirt portion that expands conically at the bottom of the guide tube is provided with a plurality of ribs that extend radially on the inner surface thereof; The rib is configured such that a pushing force, which is intensified by adding centrifugal force in a direction toward the circumferential end of the lower part of the skirt portion, pushes in the sealing water present around the skirt portion, The pressed-in seal water generates a restoring force in the direction of pushing back due to centrifugal force, The pushing force of the raw liquid and the restoring force generated by the seal water collide to form a turbulent flow at the interface between the raw liquid and the seal water, A method for separating water-soluble substances and components using a vertical centrifuge, characterized in that the formation of the turbulent flow causes the water-soluble substances and components to be extracted from the liquid to be treated and move to the sealed water side. 9. 9. The method for separating water-soluble substances and components using a vertical centrifuge as described in 8 above, wherein the water-soluble substances or components contain ammonia. 10. 9. A method for separating water-soluble substances and components using the vertical centrifuge described in 8 above, characterized in that the water-soluble substances and components contain alkali metals. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a vertical centrifuge and a method for separating water-soluble substances and components using a vertical centrifuge that can transfer water-soluble substances and components in a raw liquid to the sealed water side even when ribs on a guide cylinder are used. [Brief explanation of the drawings]

[0016] [Figure 1] Cross-sectional view showing the configuration of the main parts of a centrifuge [Figure 2] FIG. 10 is a bottom view showing a skirt portion of a guide cylinder provided in a centrifuge. [Figure 3] FIG. 10 is a cross-sectional view of a main part showing an example of a rib attachment mode. [Figure 4] FIG. 10 is a cross-sectional view of a main part showing another example of a rib attachment mode. [Figure 5] FIG. 10 is a plan view of a main part showing one shape of the rib. [Figure 6] 10 is a plan view of a main part showing other shapes of the rib; [Figure 7] An explanatory diagram of the inner surface of the guide tube from the bottom up to the water seal DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] FIG. 1 is a cross-sectional view showing the configuration of the main part of a centrifugal separator. The centrifuge 1 is a vertical centrifuge using separation plates, and the raw liquid, which is the liquid to be treated, supplied into the centrifuge 1 through the raw liquid inlet pipe 10 is separated into two phases: a light liquid (clean liquid) and a heavy liquid (separated water), or into three phases: a light liquid (clean liquid), a heavy liquid (separated water), and solids.

[0019] In this embodiment, if the oil (liquid) to be treated does not contain much water, it is sufficient to obtain purified oil (liquid), and therefore it is not intended to constantly discharge separated water. In such cases, it is sufficient to simply add seal water.

[0020] In the present invention, the raw liquid (liquid to be treated) may be, for example, a treated oil such as fuel oil or lubricating oil, and preferably, a treated oil containing ammonia (NH3), which is a water-soluble substance and component, or an treated oil containing alkali metals such as sodium (Na) or potassium (K).

[0021] In the present invention, the oil to be treated, which contains these water-soluble substances and components to be treated, is separated and removed from the oil by a vertical centrifuge equipped with a separation plate, which is an oil purifier, to obtain purified oil, which is a clean liquid.

[0022] The alkali metals contained in the oil to be treated, such as ammonia (NH3), sodium (Na), and potassium (K), are all ionized in the oil to be treated, and are mainly ammonium ions (NH4 + ), sodium ions (Na + ), potassium ions (K + ) is thought to exist.

[0023] The rotor 11 of the vertical centrifuge 1 is configured in the shape of a container, with main components including a rotor cover 12, a bottom 13, and a valve cylinder 14.

[0024] A guide tube 15 is provided on the outer periphery of the raw liquid inlet pipe 10. The guide tube 15 has a cylindrical portion 150 formed at the top and a skirt portion 151 that widens out in a conical shape formed at the bottom. Inside the rotor 11, a plurality of separation plates 17 are stacked with gaps between them on the outer periphery of the guide cylinder 15, forming a processing chamber 170.

[0025] The raw liquid flows from the raw liquid inlet pipe 10 through the cylindrical section 150, between the valve cylinder 14 and the skirt section 151, and into the treatment chamber 170 equipped with a separation plate 17, where it is centrifuged to separate the clean liquid and water. The water-soluble substances and components of the oil to be treated are separated and removed into the water.

[0026] To prevent the light liquid (clean oil) from flowing out from the outlet for the heavy liquid (separated water), water is previously poured in to form a water seal 22 that blocks the heavy liquid outlet. If a water phase is previously formed inside the rotor 11 as the water seal 22, it is possible to prevent the light liquid that has been centrifuged later from being discharged from the heavy liquid outlet, and to discharge the light liquid from the light liquid outlet.

[0027] The raw liquid is separated into a light liquid (clean oil) and a heavy liquid (separated water) by centrifugation in a treatment chamber 170 equipped with a separation plate 17. The clean oil separated in the treatment chamber 170 is guided by the upper surface of the skirt portion 151 and moves toward the central axis of the separation plate 17 , and is sent to the light liquid chamber 19 via the outer circumferential surface of the cylindrical portion 150 . The clean oil in the light liquid chamber 19 is discharged to the outside via the light liquid discharge pipe 21 by the light liquid impeller 20.

[0028] On the other hand, the separated water, which is the heavy liquid obtained by the centrifugation, is sent to the water sealing section 22. The separated water sent to the water sealing section 22 passes through the gap between the water receiving plate 18 and the rotor cover 12 and is sent to the heavy liquid chamber 23.

[0029] The water, which is the heavy liquid in the heavy liquid chamber 23, is collected as separated water by the heavy liquid impeller 24 through the heavy liquid discharge pipe 25. At this time, the water-soluble substances and components to be treated in the oil to be treated are separated to the water sealing section 22 side together with the heavy liquid (separated water).

[0030] When the oil to be treated is centrifuged in the rotor 11, the separated water accumulates as a heavy liquid in the water seal portion 22, and a vertical separation boundary surface IF is formed between the light liquid (clean oil) and the heavy liquid (water).

[0031] In order to intermittently extract water from the heavy liquid side, a discharge valve (not shown) can be provided in the heavy liquid discharge pipe 25 connected to the heavy liquid impeller 24. The raw liquid can be supplied continuously, and the heavy liquid water can be extracted intermittently.

[0032] FIG. 2 is a bottom view showing the skirt portion 151 of the guide cylinder 15 provided in the centrifugal separator.

[0033] The guide tube 15 has a cylindrical portion 150 at the top and a skirt portion 151 that widens in a conical shape at the bottom.

[0034] In this embodiment, one or more, preferably multiple, ribs 15A are provided to extend radially on the inner surface of the guide tube 15 from the cylindrical portion 150 to the skirt portion 151. The skirt portion 151 does not have an opening extending to the lower circumferential edge, and the ribs 15A extend to the lower circumferential edge of the skirt portion 151. These ribs 15A can apply an enhanced extrusion force to the stock solution by adding it to the centrifugal force in the direction toward the circumferential edge of the lower part of the skirt portion 151. In other words, the ribs 15A are extrusion force-enhancing ribs that can efficiently supply the stock solution into the rotor because they apply an enhanced extrusion force to the stock solution by adding it to the centrifugal force. 2, a plurality of semicircular notches 151B corresponding to the ribs 15A are provided at predetermined intervals on the outer circumferential portion 151A of the skirt portion 151 of the guide tube 15. Although an example in which the notches 151B are provided is shown in FIG. 2, they may not be provided.

[0035] Furthermore, by applying a pushing force from the inside of the skirt portion 151 area to the outside of the area by the rib 15A, the sealing water of the water sealing portion 22 outside the area can be pushed in.

[0036] The rib 15A preferably extends to the vicinity of the upper end of the cylindrical portion inside the guide cylinder 15. The rib 15A also extends to the outer periphery 151A of the skirt portion 151 as shown in FIG. The number of ribs 15A is eight in the illustrated example, but is not particularly limited to this number.

[0037] As shown in FIG. 3, the rib 15A may be in the shape of an L-shape and detachably fastened with a pin 152 along a groove 153 on the inner surface of the skirt portion 151, or as shown in FIG. 4, the rib 15A may be a square rod-shaped member that is detachably attached along the groove 153. The rib 15A may be formed integrally with the skirt portion 151 on the inner surface of the skirt portion 151, or may be fixed to the inner surface of the skirt portion 151 by welding.

[0038] The rib 15A may be straight as shown in FIG. 2, partially bent as shown in FIG. 5, or curved as shown in FIG.

[0039] The raw liquid inlet pipe 10 is inserted into the axial center of the guide cylinder 15. The guide cylinder 15 rotates, but the raw liquid inlet pipe 10 does not rotate.

[0040] FIG. 7 is a diagram showing a schematic view of the flow of the concentrate around the lower surface of the skirt portion 151. As shown in FIG. As described above, the raw liquid, which is the oil to be treated, is introduced into the center of the guide cylinder 15 from the raw liquid inlet pipe 10. In Figure 7, the arrows along the circumference of the cross section of the raw liquid inlet pipe 10 exemplarily indicate the direction of rotation of the guide cylinder 15, and the arrows along the rib 15A indicate the direction of travel of the raw liquid.

[0041] The separation boundary surface (IF) of the water seal portion 22 is located around the skirt portion 151, and the raw liquid flows toward the water seal portion 22 and forms a turbulent flow portion 27 at the portion where it reaches the water seal portion 22. In the illustrated example, the turbulent flow portions 27 are formed near the tips of the ribs 15A.

[0042] Because the guide tube 15 is installed inside the rotor, centrifugal force acts on the concentrate passing between the valve cylinder 14 and the skirt portion 151. Here, the presence of the ribs 15A creates an effect of efficiently sucking in the concentrate, and an intensified pressing force is added to the centrifugal force and acts on the concentrate, pushing it out. The force pushing out the concentrate is a combination of the centrifugal force and the additional force due to the presence of the ribs 15A.

[0043] The extruded concentrate comes into contact with the seal water of the water seal portion 22 located on the outside of the rotor. That is, the concentrate is subjected to centrifugal force by the rib 15A in the direction toward the outer periphery 151A of the skirt portion 151, the extrusion force is strengthened, and the concentrate to which the pushing force is applied comes into contact with the seal water present around the skirt portion 151. Then, when the concentrate comes into contact, the extruding force acts on the concentrate, which acts to push the seal water.

[0044] However, since centrifugal force is also at work while this action is occurring, a restoring force is generated in the seal water, and the restoring force (repulsive force) from the seal water acts on the pressed-in raw liquid. The pushing action of the raw liquid against the seal water and the pushing back action of the seal water due to the repulsive force of the centrifugal force against the raw liquid result in a collision of complex flows in multiple directions rather than in one direction, causing turbulence to occur below the rotating body.

[0045] Here, turbulence means that the linear separation boundary surface formed between liquids with different specific gravities by centrifugal separation is disturbed and no longer linear.

[0046] The formation of such turbulence causes water-soluble substances and components in the raw solution, such as ammonia and alkali metals such as sodium and potassium, to migrate from the oil to be treated (raw solution) to the seal water side.

[0047] Therefore, the rib 15A provided on the skirt portion 151 generates the above mechanism, which efficiently separates water-soluble substances and components from the raw liquid and enables the clean oil from which the water-soluble substances and components have been separated to be continuously or intermittently discharged from the rotating body.

[0048] 7 shows an example in which the notch 151B is not provided, but the notch 151B may be provided. In this case, the rib 15A of the guide tube 15 suppresses the loss of the centrifugal force applied to the concentrate, allowing the concentrate to contact the separation boundary surface of the seal water. This increases the force that peels off the oil film that covers the water-soluble substances and components, making it easier for the water-soluble substances and components to migrate to the seal water side.

[0049] Ammonia gets mixed into lubricating oil when it is burned in engines, etc., so the lubricating oil mixed with ammonia is sent to a centrifugal separator, which is an oil purifier, and the mixed ammonia is transferred to the seal water side of the oil purifier and separated using the mechanism described above.

[0050] Here, the behavior of ammonia in oil will be explained. When ammonia is mixed into lubricating oil, it is difficult for the ammonia to escape from the oil unless it is subjected to stress such as heating, pressure, impact, decompression, etc. This is thought to be because the ammonia is covered by an oil film, making it difficult to escape.

[0051] As described above, in the operating method using the rotor structure including the rib 15A of the guide tube 15 of the oil purifier and the seal water, if there is no turbulent mixing of the lubricating oil and the seal water, the migration of ammonia to the seal water does not progress, and even if it progresses, if the migration of ammonia is small, ammonia remains in the oil, and the purpose of centrifugal separation cannot be achieved.

[0052] To summarize again, in the present invention, multiple ribs 15A are installed on the skirt portion 151 at the bottom of the guide tube 15, and the area where these multiple ribs 15A are located has the effect of applying centrifugal force to the concentrate, pushing the concentrate into the rotating body.

[0053] The pushed-out stock solution comes into contact with the seal water located on the outside of the rotor. When they come into contact, the stock solution exerts a pushing force, which acts to push into the seal water, and then centrifugal force creates a force that causes the seal water to return to its original state. This pushing action of the stock solution against the seal water and the pushing back action of the seal water due to the centrifugal force, which causes the seal water to repel the stock solution, result in a complex flow collision in multiple directions rather than in a single direction, which creates turbulence at the bottom of the rotor. This turbulence can peel off the oil film that covers the ammonia, allowing the ammonia to migrate to the seal water side and separate from the oil.

[0054] In this embodiment, oil to be treated containing water-soluble substances and alkali metal components such as sodium (Na) and potassium (K) can also be separated and removed in the same manner. For example, alkali metals such as sodium and potassium may be mixed into gas turbine engines used in marine structures, etc., depending on the installation conditions of the tanks that store fuel oil (equivalent to MGO / diesel oil), or may be mixed in during the transportation of fuel oil (equivalent to MGO / diesel oil). The presence of alkali metals such as sodium and potassium may cause corrosion due to vanadium attack during operation of the gas turbine engine.

[0055] The turbulent agitation mechanism described above allows alkali metals such as sodium and potassium that have been mixed into the fuel oil during pretreatment to be separated by migrating them to the seal water side of the oil purifier. This is a preferred embodiment because gas turbine engines for offshore structures are expensive.

[0056] As described above, by implementing the vertical centrifuge and the method for separating water-soluble substances and components using a vertical centrifuge according to the present invention, the water-soluble substances and components in the raw liquid can be removed from the clean oil (light liquid side) and transferred to the seal water side, and the clean oil from which the water-soluble substances and components have been removed can be discharged. [Explanation of symbols]

[0057] 1. Centrifuge 10 Stock solution inflow pipe 11 Rotating body 12 Rotating lid 13 Bottom 14-valve cylinder 15 Guide tube 15A Rib 150 Cylindrical body part 151 Skirt Club 151A outer periphery 151B Notch 152 pins 153 Groove 17 Separation plate 170 Processing Room 18 Water tray board 19 Light Liquid Chamber 20 Light Liquid Impeller 21 Light liquid discharge pipe 22 Water sealing section 23 Heavy Liquid Chamber 24 Heavy-liquid impeller 25 Heavy liquid discharge pipe 26 Adjustment board 27 Turbulence section

Claims

1. A vertical centrifuge in which a raw liquid to be treated is introduced into a treatment chamber having a plurality of separation plates on the outer periphery of a guide cylinder, and a clean liquid is obtained on the light liquid side, a plurality of ribs extending radially to an outer periphery of an inner surface of a skirt portion expanding conically at a lower portion of the guide tube; the rib applies centrifugal force to the concentrate when the concentrate is positioned in a direction toward the circumferential edge of the lower part of the skirt portion, thereby increasing the extrusion force; The extrusion force of the concentrate is increased by the ribs, and the seal water existing around the skirt portion is pushed out. A restoring force is generated in the pushed-in seal water by centrifugal force in the pushing-back direction, The pushing force of the raw liquid and the restoring force generated in the seal water collide to form a turbulent flow at the boundary between the raw liquid and the seal water, The vertical centrifugal separator is characterized in that the rib is detachably provided on the inner surface of the skirt portion.

2. 2. A vertical centrifuge according to claim 1, wherein the formation of the turbulent flow extracts water-soluble substances and components from the liquid to be treated and transfers them to the sealed water side.

3. 3. The vertical centrifuge according to claim 2, wherein the water-soluble substances and components include ammonia.

4. 3. The vertical centrifuge according to claim 2, wherein the water-soluble substance and the component contain an alkali metal.

5. 2. The vertical centrifuge according to claim 1, wherein the rib extends to the inside of the guide cylinder.

6. 2. The vertical centrifuge according to claim 1, wherein a plurality of semicircular notches are formed at predetermined intervals on the outer periphery of said skirt portion.

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