Liquid separation system and liquid separation method

Abstract

To provide a liquid separation system that can more precisely separate a stock solution into a light liquid and a heavy liquid. [Solution] The liquid separation system 1 comprises a centrifugal separator 2 that separates a raw liquid US containing light liquid and heavy liquid into a first liquid LF1 mainly composed of light liquid and a second liquid HF1 mainly composed of heavy liquid, a coalescer filter 3 to which the separated liquid SS1 consisting of the first liquid LF1 or the second liquid HF1 is supplied, and a housing 5 that houses the coalescer filter 3. The coalescer filter 3 causes the minute heavy liquid or minute light liquid remaining in the separated liquid SS1 to grow into coarse droplets, and as the coarse droplets settle or float, a light liquid layer LF2 mainly composed of light liquid and a heavy liquid layer HF2 mainly composed of heavy liquid are formed inside the housing 5.

Description

Technical Field

[0001] The present invention relates to a liquid separation system and a liquid separation method.

Background Art

[0002] Generally, as an apparatus for separating a stock solution containing a light liquid such as oil and a heavy liquid such as water into the light liquid and the heavy liquid, for example, a centrifuge as described in Patent Document 1 is known.

[0003] As characteristics of a centrifuge as described in Patent Document 1, large particles, coarse particles, particles with a large mass, and droplets can be more easily separated because the centrifugal force acting on them is greater as they are larger.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a centrifuge as described in Patent Document 1, when separating the stock solution more precisely into the light liquid and the heavy liquid, the centrifugal force acting on fine and small - mass particles and small droplets present in the stock solution becomes smaller, so there is a problem that they cannot be completely captured by the centrifuge and flow out to the downstream side.

[0006] An object of the present invention is to solve the above - mentioned problems and provide a liquid separation system and a liquid separation method capable of separating a stock solution more precisely into a light liquid and a heavy liquid.

Means for Solving the Problems

[0007] To solve the aforementioned problems, the first liquid separation system of the present invention includes a centrifuge that separates a stock solution containing a light liquid and a heavy liquid into a first liquid mainly composed of the light liquid and a second liquid mainly composed of the heavy liquid, The system comprises a coalescer filter to which a separation liquid consisting of the second liquid is supplied, and a housing that houses the coalescer filter, wherein the coalescer filter captures and aggregates minute light liquids remaining in the separation liquid, causing them to grow into coarse droplets, and the coarse droplets float within the housing due to the difference in specific gravity between them and the heavy liquid, thereby forming a light liquid layer mainly consisting of the light liquid and a heavy liquid layer mainly consisting of the heavy liquid within the housing. It is.

[0009] Furthermore, the liquid separation method of the present invention is Using the first liquid separation system, The first step involves supplying a stock solution containing heavy liquid and light liquid to a centrifuge and separating it into a first liquid mainly composed of the light liquid and a second liquid mainly composed of the heavy liquid. A second step involves supplying a separation solution consisting of the first liquid or the second liquid to a coalescer filter. A third step involves growing the minute heavy liquid or minute light liquid remaining in the separated liquid into coarse droplets, A fourth step involves separating the coarsely sized droplets into a heavy liquid layer mainly composed of the heavy liquid and a light liquid layer mainly composed of the light liquid by allowing them to settle or float. It includes that. [Effects of the Invention]

[0010] The liquid separation system and liquid separation method of the present invention can more precisely separate a stock liquid into a light liquid and a heavy liquid. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing a liquid separation system and liquid separation method according to the first embodiment. [Figure 2A] This is a schematic diagram of the filter section, which contains a coalescer filter within the enclosure. [Figure 2B] This is a schematic diagram showing that the separated liquid is supplied to the filter section and coarse droplets of heavy liquid are formed outside the coalescer filter. [Figure 2C] This is a schematic diagram showing that the separated liquid is supplied to the filter section and coarse droplets of heavy liquid are formed outside the coalescer filter. [Figure 2D] This is a schematic diagram illustrating the formation of a heavy liquid layer and a light liquid layer within the enclosure. [Figure 2E]It is a process diagram of the liquid separation method according to the first embodiment. [Figure 3A] It is a schematic configuration diagram showing a liquid separation system and a liquid separation method according to the second embodiment. [Figure 3B] It is a schematic diagram of supplying a separated liquid to a water-repellent filter unit according to the second embodiment and removing moisture as water droplets. [Figure 4] It is a schematic configuration diagram showing a liquid separation system and a liquid separation method according to the third embodiment. [Figure 5] It is a schematic configuration diagram showing a liquid separation system and a liquid separation method according to the fourth embodiment. [Figure 6] It is a schematic configuration diagram showing a liquid separation system and a liquid separation method according to the fifth embodiment. [Figure 7] It is a schematic configuration diagram showing a liquid separation system and a liquid separation method according to the sixth embodiment.

Embodiments for Carrying Out the Invention

[0012] [First Embodiment] The liquid separation system 1 and the liquid separation method according to the first embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2A to 2E. FIG. 1 is a schematic configuration diagram showing a liquid separation system 1 and a liquid separation method according to the first embodiment, and shows a case where a stock solution US containing a heavy liquid in a light liquid is separated by the liquid separation system 1. FIG. 2A is a schematic diagram of a filter unit 50 including a coalescer filter 3 in a housing 5. In the following description, the vertical direction is described as the vertical direction orthogonal to the upper surface of the housing 5 of the coalescer filter 3 in FIGS. 1, 2A to 2D.

[0013] ≪Liquid Separation System≫ As shown in FIG. 1, the liquid separation system 1 is a device that separates an undiluted solution US (Undiluted Solution (hereinafter referred to as "US")) containing a light liquid and a heavy liquid into the light liquid and the heavy liquid. The liquid separation system 1 includes a centrifuge 2, a stock solution supply pipe 22, a separated light liquid supply pipe 23, a separated heavy liquid outlet pipe 24, a coalescer filter 3, a housing 5, a return flow path 33, and a discharge pipe 34.

[0014] ≪Stock Solution, Light Liquid, and Heavy Liquid≫ The stock solution US is a liquid containing a light liquid with a lower specific gravity and a heavy liquid with a higher specific gravity than the light liquid. The light liquid is, for example, oils such as kerosene, light oil, aircraft fuel, gasoline, etc. The heavy liquid is, for example, water or the like with a higher specific gravity than oils.

[0015] <First Liquid and Second Liquid> The first liquid LF1 (Light Fluids 1 (hereinafter referred to as "LF1")) and the second liquid HF1 (Heavy Fluids 1 (hereinafter referred to as "HF1")) are liquids separated from the stock solution US by the centrifuge 2. The first liquid LF1 is a liquid mainly composed of the light liquid, and is a light liquid with a lower specific gravity that gathers near the rotation axis when the stock solution US is centrifuged by the centrifuge 2. The proportion of the light liquid in the first liquid LF1 is, for example, 90% or more. The second liquid HF1 is a liquid mainly composed of the heavy liquid, and is a heavy liquid with a higher specific gravity that gathers at a position far from the rotation axis when the stock solution US is centrifuged by the centrifuge 2. The proportion of the heavy liquid in the second liquid HF1 is, for example, 90% or more.

[0016] Here, examples of the main liquids sequentially described in this embodiment are given. The "stock solution US" is the liquid to be separated this time, which contains a light liquid with a lower specific gravity and a heavy liquid with a higher specific gravity than the light liquid. The "first liquid LF1" is a liquid mainly composed of the light liquid LL, and is a light liquid with a lower specific gravity that gathers near the rotation axis of the centrifuge 2 when the stock solution US is centrifuged by the centrifuge 2 (see FIG. 1). "Second liquid HF1" is a liquid mainly composed of heavy liquid MD, and is the heavier liquid that collects at a position far from the rotation axis of centrifuge 2 when the stock liquid US is centrifuged in centrifuge 2 (see Figure 1). "Separated liquid SS1" refers to the liquid consisting of the first liquid LF1 separated from the raw liquid US by the centrifuge 2 (see Figure 1). "Light liquid LL" refers to the liquid that separates from the separation liquid SS1 within the housing 5 (described later) and forms the main component of the light liquid layer LF2. "Heavy liquid MD" is the liquid that separates from the separation liquid SS1 within the housing 5 described later, and becomes the main component of the heavy liquid layer HF2. "Minor heavy liquid MD1" refers to the minute amount of heavy liquid dispersed within the separation liquid SS1, as will be explained later. "Coarsely processed heavy liquid MD2" refers to heavy liquid that has been coarsened by the aggregation of heavy liquid MD1, as will be explained later.

[0017] ≪Centrifugal separator≫ The centrifuge 2 uses centrifugal force generated by a rotating rotor (not shown) to separate the raw liquid US into a first liquid LF1 and a second liquid HF1. ​​As shown in Figure 1, the centrifuge 2 consists of, for example, a stacked separation plate type centrifuge with a built-in pump (not shown). When the raw liquid US is supplied into the centrifuge 2, the first liquid LF1, which has a lower specific gravity, gathers on the side of the rotating shaft, and the second liquid HF1, which has a higher specific gravity, gathers on the outer circumference. The centrifuge 2 is composed of a casing 21, a rotor (not shown), and a pump (not shown).

[0018] <Casing> As shown in Figure 1, the casing 21 is a component that forms the entire outer frame of the centrifuge 2. The casing 21 has a supply port 21a, a separation heavy liquid discharge port 21b, and a separation light liquid discharge port 21c. Note that the centrifuge 2 in Figure 1 is a schematic representation, and the positions of the supply port 21a, separation heavy liquid discharge port 21b, and separation light liquid discharge port 21c are not limited to those shown.

[0019] The supply port 21a is the inlet for the undiluted solution US. The undiluted solution supply pipe 22 is connected to the supply port 21a. The separated heavy liquid discharge port 21b is the outlet for the second liquid HF1. ​​The separated heavy liquid outlet pipe 24 is connected to the separated heavy liquid discharge port 21b. The separated light liquid discharge port 21c is the outlet for the first liquid LF1. The separated light liquid supply pipe 23 is connected to the separated light liquid discharge port 21c.

[0020] <Stock solution supply pipe> As shown in Figure 1, the stock solution supply pipe 22 is a stock solution supply channel for supplying stock solution US from a source (not shown) to the centrifuge 2. The downstream side of the stock solution supply pipe 22 is connected to the supply port 21a of the centrifuge 2.

[0021] <Separated light liquid supply pipe> As shown in Figure 1, the separation light liquid supply pipe 23 is a light liquid supply channel for supplying the separated liquid SS1, which consists of the first liquid LF1 separated from the raw liquid US by the centrifuge 2, to the coalescer filter 3. The upstream side of the separation light liquid supply pipe 23 is connected to the separation light liquid discharge port 21c, and as shown in Figure 2A, the downstream side is inserted into the coalescer filter 3 as an internal piping section 23-1.

[0022] The separated liquid SS1 is pressurized by an impeller built into the centrifuge 2 and transferred via the separated light liquid supply pipe 23. If the separated liquid SS1 overflows from the centrifuge 2, it may be stored in a tank or similar container before being transferred by a separate pump.

[0023] Multiple through-holes 23a are formed in the internal piping section 23-1 of the separation light liquid supply pipe 23 that is inserted into the coalescer filter 3. The separation liquid SS1 supplied to the separation liquid supply pipe 23 is discharged from the through-holes 23a and supplied into the coalescer filter 3. The lower end of the separation light liquid supply pipe 23 is closed with a plug member 231, and the separation light liquid supply pipe 23 and the coalescer filter 3 are fixed by screwing the plug member 231 and the filter support member 31B together with a bolt 232.

[0024] <Separated heavy liquid outlet pipe> As shown in Figure 1, the separated heavy liquid outlet pipe 24 is a separated heavy liquid outlet passage for discharging the second liquid HF1 separated from the raw liquid US by the centrifuge 2. The upstream side of the separated heavy liquid outlet pipe 24 is connected to the separated heavy liquid discharge port 21b of the centrifuge 2.

[0025] If the raw US solution contains solids, these solids are separated into solid and liquid components by the centrifuge 2 and discharged separately from the separated heavy liquid outlet pipe 24 through a separate discharge pipe (not shown). In this embodiment, since the centrifuge 2 is located upstream of the coalescer filter 3, the solids in the raw US solution are removed before reaching the coalescer filter 3, preventing clogging of the coalescer filter 3.

[0026] <Coalescer filter> As shown in Figure 1, the coalescer filter 3 is a filter capable of separating oil and water from a water-mixed oil containing water, for example. As shown in Figure 2A, the coalescer filter 3 comprises a hollow filter material 30, filter support members 31 (31A, 31B) provided above and below the filter material 30, and packings 32 (32A, 32B) provided between the filter material 30 and the filter support members 31A, 31B, respectively.

[0027] Furthermore, as shown in Figures 2B and 2C, the separated liquid SS1 supplied by the separated light liquid supply pipe 23 is discharged from inside the separated light liquid supply pipe 23 toward the coalescer filter 3 outside the pipe through a through-hole 23a provided in the internal piping section 23-1 within the coalescer filter 3 of the separated light liquid supply pipe 23.

[0028] As shown in Figures 2B and 2C, the separated liquid SS1 is pumped into the inside (central part) of the coalescer filter 3 by the separation light liquid supply pipe 23. In the process of moving from the inside to the outside of the filter material 30 of the coalescer filter 3, the coalescer filter 3 captures the minute heavy liquid (free water droplets) MD1 dispersed in the separated liquid SS1, causing the minute heavy liquid MD1 to aggregate and grow into coarse heavy liquid MD2. As a result, this coarse heavy liquid MD2 is separated from the separated liquid SS1.

[0029] In this embodiment, the majority of the separated liquid SS1 is light liquid LL. As a result, as shown in Figure 2D, the separated coarse droplets (droplets of heavy liquid MD in this embodiment), coarse heavy liquid MD2, settle in the light liquid layer LF2 outside the coalescer filter 3 due to the difference in specific gravity with the light liquid LL, and accumulate at the bottom of the housing 5 to form the heavy liquid layer HF2. The light liquid LL remaining after separating the coarse droplets accumulates at the top of the housing 5 to form the light liquid layer LF2.

[0030] In this way, the coalescer filter 3 can more reliably separate the separated liquid SS (first liquid LF1, mainly light liquid in this embodiment) discharged from the centrifuge 2 into light liquid and heavy liquid.

[0031] As shown in Figure 2D, the separated liquid SS1 introduced into the coalescer filter 3 separates into a light liquid layer LF2, mainly composed of light liquid LL, and a heavy liquid layer HF2, mainly composed of heavy liquid MD, inside the housing 5. The first liquid (light liquid) L1, extracted from the upper light liquid layer LF2, is sent to the discharge pipe 34 from the top of the housing 5. In contrast, the second liquid (heavy liquid) L2, extracted from the lower heavy liquid layer HF2, is discharged from the return channel 33 located at the bottom of the housing 5. The boundary line BL illustrates the boundary between the heavy liquid layer HF2 and the light liquid layer LF2.

[0032] <Enclosure> As shown in Figures 1 and 2A, the housing 5 is a tank-shaped sealed container that houses the coalescer filter 3, the light liquid LL, and the heavy liquid MD. Inside the housing 5, the coarse heavy liquid MD2 separated by the coalescer filter 3 settles due to the difference in specific gravity with the light liquid LL, while the light liquid LL from which the coarse heavy liquid MD2 has been separated floats to the surface. As a result, a light liquid layer LF2 mainly composed of light liquid LL and a heavy liquid layer HF2 mainly composed of heavy liquid MD are formed inside the housing 5.

[0033] As shown in Figure 2A, the housing 5 is composed of a cylindrical body 51, a lid portion (upper flange 52) provided to close the upper end of the cylindrical body 51, and a bottom portion (lower flange 53) provided to close the lower end of the cylindrical body 51. The housing 5 has a heavy liquid outlet 5a to which a return channel 33 is connected for the discharge of heavy liquid MD separated by sedimentation, and a light liquid outlet 5b to which a discharge pipe 34 is connected for the discharge of light liquid LL separated by flotation. The filter system (filter section 50) is formed by enclosing the coalescer filter 3 within the housing 5.

[0034] As shown in Figure 2A, the coalescer filter 3 is mounted on the upper flange 52 so as to hang down via the separation light liquid supply pipe 23. The heavy liquid outlet 5a is formed on the lower flange 53 which forms the bottom surface of the housing 5. The light liquid outlet 5b is formed near the upper side of the cylindrical body 51 which forms the upper side surface of the housing 5.

[0035] <Return channel> As shown in Figures 1 and 2D, the return channel 33 is a channel for supplying the second liquid (heavy liquid MD) L2, which constitutes the heavy liquid layer HF2 in the housing 5, to the upstream side of the centrifuge 2. The upstream side of the return channel 33 is connected to the heavy liquid outlet 5a, and the downstream side is connected to the stock liquid supply pipe 22. The second liquid (heavy liquid MD) L2 returned to the stock liquid supply pipe 22 by the return channel 33 is mixed with the stock liquid US and reintroduced to the centrifuge 2.

[0036] <Exhaust pipe> As shown in Figures 1 and 2D, the discharge pipe 34 is a flow path for discharging the liquid constituting the light liquid layer LF2 inside the housing 5 to the outside of the housing 5. The upstream side of the discharge pipe 34 is connected to the light liquid outlet 5b. Therefore, the discharge pipe 34 can discharge only the light liquid LL of the light liquid layer LF2, which is separated by flotation within the housing 5 from the first liquid LF1 separated by centrifugal force in the centrifuge 2, from inside the housing 5.

[0037] ≪Effect≫ Next, the operation of the liquid separation system 1 and liquid separation method according to the first embodiment of the present invention will be described with reference to Figures 1, 2A to 2E.

[0038] Figure 2E is a process diagram of the liquid separation method according to the first embodiment. First, as shown in Figure 2E, the stock solution US containing heavy liquid and light liquid is supplied to the centrifuge 2 from the stock solution supply pipe 22. The stock solution US supplied to the centrifuge 2 is centrifuged within the centrifuge 2 into a first liquid LF1 mainly consisting of light liquid and a second liquid HF1 mainly consisting of heavy liquid (first step: S1).

[0039] Next, the separation liquid SS1, consisting of the first liquid LF1, is supplied into the coalescer filter 3 by the separation light liquid supply pipe 23 (second step: S2). In the coalescer filter 3, the coalescer filter 3 captures and coagulates the minute heavy liquid MD1 remaining in the separation liquid SS1, separating it from the separation liquid SS1 as coarse heavy liquid MD2 (third step: S3).

[0040] The coarse heavy liquid MD2 separated by the coalescer filter 3 is allowed to settle inside the housing 5, thereby separating the separated liquid SS1 supplied from the centrifuge 2 into a heavy liquid layer HF2 mainly consisting of heavy liquid MD and a light liquid layer LF2 mainly consisting of light liquid LL (fourth step: S4).

[0041] Next, the second liquid (heavy liquid MD) L2, which constitutes the heavy liquid layer HF2, is sent to the stock liquid supply pipe 22 via the return channel 33 and mixed with the stock liquid US (fifth step: S5). The liquid sent to the centrifuge 2 is then separated into light liquid LL and heavy liquid MD by repeating the first step (S1), second step (S2), third step (S3), fourth step (S4), and fifth step (S5).

[0042] Therefore, the heavy liquid MD, which consists of water and remains in the first liquid LF1 because it could not be completely centrifuged by the centrifuge 2, can be further separated. As a result, it becomes possible to obtain a light liquid (first liquid L1) consisting of oil that has been separated with high precision, which is the target of purification.

[0043] In this example, the heavy liquid was described as "water" and the light liquid as "oil." However, the liquid separation system 1 according to this embodiment is not limited to "water" as the heavy liquid and "oil" as the light liquid. As long as the raw liquid US contains a light liquid and a heavy liquid with different specific gravities, it can be precisely separated into the light liquid and the heavy liquid.

[0044] As shown in Figure 1, the liquid separation system 1 includes a centrifuge 2 that separates a raw liquid US containing light liquid LL and heavy liquid MD into a first liquid LF1 mainly composed of light liquid LL and a second liquid HF1 mainly composed of heavy liquid MD; a coalescer filter 3 to which the separated liquid SS1 consisting of the first liquid LF1 is supplied; and a housing 5 that houses the coalescer filter 3. The coalescer filter 3 separates the minute heavy liquid MD1 remaining in the separated liquid SS1 from the separated liquid SS1, forming a light liquid layer LF2 mainly composed of light liquid LL and a heavy liquid layer HF2 mainly composed of heavy liquid MD within the housing 5.

[0045] The liquid separation system 1 according to this embodiment has a coalescer filter 3, which captures, aggregates, and coarses fine, small droplets that could not be centrifuged by the centrifuge 2, enabling efficient and precise liquid-liquid separation. As a result, even when a centrifuge 2 with a small rated processing capacity is selected, precise separation of light liquids and heavy liquids becomes possible, reducing the installation space and size of the centrifuge 2, thereby reducing operating power and further reducing costs.

[0046] Furthermore, as shown in Figure 1, the liquid separation system 1 is further equipped with a return channel 33 that returns the second liquid L2 (liquid) constituting the heavy liquid layer HF2 separated by the coalescer filter 3 back to the raw liquid supply pipe 22 that supplies the raw liquid US to the centrifuge 2.

[0047] With this configuration, the heavy liquid MD in the housing 5 can be returned to the centrifuge 2 via the return channel 33, and even if some light liquid remains in the heavy liquid MD due to reasons such as a small difference in specific gravity between the light liquid LL and the heavy liquid MD, the light liquid and heavy liquid can be reliably separated.

[0048] Furthermore, as shown in Figure 1, the liquid separation method of this embodiment includes a first step (S1) of supplying a raw liquid US containing heavy liquid and light liquid to a centrifuge 2 and separating it into a first liquid LF1 mainly consisting of light liquid and a second liquid HF1 mainly consisting of heavy liquid; a second step (S2) of supplying the separated liquid SS1 consisting of the first liquid LF1 to a coalescer filter 3; a third step (S3) of the coalescer filter 3 capturing and agglomerating the minute heavy liquid MD1 remaining in the separated liquid SS1 and growing it into coarse droplets MD2; and a fourth step (S4) of separating the coarse droplets MD2 into a heavy liquid layer HF2 mainly consisting of heavy liquid MD and a light liquid layer LF2 mainly consisting of light liquid LL by allowing them to settle due to the difference in specific gravity between them and the light liquid LL.

[0049] In other words, in the liquid separation method of this embodiment, the light liquid LL and heavy liquid MD contained in the separated liquid SS1 discharged from the centrifuge 2 are further separated by the coalescer filter 3, so that the heavy liquid and light liquid can be reliably separated.

[0050] Furthermore, in the liquid separation method of this embodiment, as shown in Figure 1, the liquid constituting the heavy liquid layer HF2 is mixed with the raw liquid US upstream of the centrifuge 2.

[0051] With this configuration, the heavy liquid MD in the heavy liquid layer HF2 is returned to the stock liquid US and mixed, and as a result, it is subjected to centrifugal force in the centrifuge 2 and becomes included in the second liquid HF1.

[0052] [Second Embodiment] Next, referring to Figures 3A and 3B, the liquid separation system 1A and liquid separation method according to the second embodiment will be described, focusing on the differences from the liquid separation system 1 (see Figure 1) and liquid separation method according to the first embodiment. Note that components already described are denoted by the same reference numerals and their descriptions are omitted. Figure 3A is a schematic diagram showing the liquid separation system 1A and liquid separation method according to the second embodiment.

[0053] As shown in Figure 3A, the liquid separation system 1A according to the second embodiment differs from the first embodiment in that a water-repellent filter 4 having water-repellent properties is housed within the housing 5A of the filter section 50A.

[0054] Furthermore, the liquid separation system 1A according to the second embodiment includes a coalescer filter 3 and a water-repellent filter 4, which is positioned to the side of the coalescer filter 3 and has water-repellent properties, within the housing 5A of the filter section 50A. The coalescer filter 3 and the water-repellent filter 4 are installed so as to hang down from the lid portion (upper flange 52A) of the housing 5A. The coalescer filter 3 is positioned around a supply pipe (separation light liquid supply pipe 23) which is inserted into the interior of the housing 5A by passing through the lid portion (upper flange 52A) of the housing 5A. The water-repellent filter 4 is inserted into the interior of the housing 5A by passing through the lid portion (upper flange 52A) of the housing 5A and is positioned around a discharge pipe 34A that discharges the separated liquid from the water-repellent filter 4. The return flow path 33 is connected to the lower part of the housing 5A.

[0055] The housing 5A comprises a cylindrical body 51A, a lid portion (upper flange 52A) provided to close the upper end of the cylindrical body 51A, and a bottom portion (lower flange 53A) provided to close the lower end of the cylindrical body 51A. Inside the housing 5A, a coalescer filter 3 and water-repellent filters 4 are housed to the side of the coalescer filter 3, spaced horizontally at appropriate intervals. For this reason, the housing 5A is larger laterally than the housing 5 shown in Figure 1.

[0056] As shown in Figure 3A, a heavy liquid outlet 5Aa, to which the return channel 33 is connected, is provided in the center of the lower flange 53A that constitutes the bottom surface of the housing 5A. In other words, the heavy liquid outlet 5Aa is located below the coalescer filter 3 and the water-repellent filter 4 within the housing 5A.

[0057] Within the housing 5A, the separated liquid SS1 (a liquid mainly consisting of light liquid with a small amount of heavy liquid remaining) supplied from the separated light liquid supply pipe 23 is separated into light liquid LL and heavy liquid MD by the coalescer filter 3 and discharged into the housing 5A. The heavy liquid MD discharged into the housing 5A settles within the housing 5A to form a heavy liquid layer HF2, while the light liquid LL floats within the housing 5A to form a light liquid layer LF2 mainly consisting of light liquid LL.

[0058] The heavy liquid (second liquid L2) from the separated heavy liquid layer HF2 is sent to the centrifuge 2 via the return channel 33 from the heavy liquid outlet 5Aa. Here, the heavy liquid (second liquid L2) of the heavy liquid layer HF2 containing water W and solids, which has been sent to the centrifuge 2 via the return channel 33, is again separated and removed in the centrifuge 2 as the second liquid HF1, where the heavy liquid containing solids remains.

[0059] A discharge pipe 34A is inserted into the water-repellent filter 4, and the light liquid that has passed through the water-repellent filter 4 is discharged through the discharge pipe 34A. In this way, the water-repellent filter 4 can suppress the mixing of water into the light liquid and further improve the purity of the light liquid.

[0060] The liquid separation system 1A of the second embodiment has a water-repellent filter 4 inside the housing 5A, which allows for the removal of water W and solids from the light liquid LL in the light liquid layer LF2 separated by flotation. This increases the purity of the light liquid discharged from the housing 5A. Furthermore, since the housing 5A houses both the coalescer filter 3 and the water-repellent filter 4 in a single housing 5A, the assembly man-hours and number of parts can be reduced compared to installing the coalescer filter and water-repellent filter equipment separately, thereby reducing costs.

[0061] Furthermore, since the water-repellent filter 4 is positioned around the internal piping section 34A-1, which is part of the discharge pipe 34A inside the housing 5A, the light liquid LL that has been separated by flotation inside the housing 5A can be further purified by removing water and solids before being discharged from the discharge pipe 34A.

[0062] In other words, as shown in Figure 3B, around the water-repellent filter 4, moisture W is separated and falls as droplets, and the light liquid LLL from which moisture W and solid matter have been removed is introduced into the internal piping section 23-1 and discharged.

[0063] [Third Embodiment] Next, referring to Figure 4, the liquid separation system 1B and liquid separation method according to the third embodiment will be explained, focusing on the differences from the liquid separation system 1 according to the first embodiment (see Figure 1). Figure 4 is a schematic diagram showing the liquid separation system 1B and liquid separation method according to the third embodiment.

[0064] As shown in Figure 4, the liquid separation system 1B according to the third embodiment differs from the first embodiment in that the stock solution US containing light liquid and heavy liquid has a larger ratio of heavy liquid to light liquid than the stock solution US of the first practical embodiment.

[0065] Furthermore, the liquid separation system 1B of the third embodiment differs from the first embodiment in that it discharges the first liquid LF1, which mainly consists of the light liquid separated from the raw liquid US by the centrifuge 2, to the outside of the liquid separation system 1B through the separated light liquid outlet pipe 26.

[0066] Furthermore, the liquid separation system 1B of the third embodiment differs from the first embodiment in that it supplies the second liquid HF1 (a liquid mainly consisting of heavy liquid and containing a small amount of light liquid) separated from the raw liquid US by the centrifuge 2 as separated liquid SS2 to the inside (central part) of the coalescer filter 3 from the separated heavy liquid supply pipe 25. The coalescer filter 3 captures and aggregates the minute light liquid in the separated liquid SS2 supplied from the centrifuge 2, causing it to grow into coarse droplets, thereby separating the heavy liquid from the separated liquid SS2. The coarse droplets (light liquid) that flow out to the outside of the coalescer filter 3 float inside the housing 5B due to the difference in specific gravity with the heavy liquid, so that the heavy liquid layer HF2, mainly consisting of heavy liquid, and the light liquid layer LF2, mainly consisting of light liquid, can be separated inside the housing 5B.

[0067] Furthermore, the liquid separation system 1B of the third embodiment differs from the first embodiment in that it returns the light liquid LL of the light liquid layer LF2 separated by flotation within the housing 5B of the filter section 50B as the first liquid L1 to the raw liquid supply pipe 22 upstream of the centrifuge 2 via the return channel 33B.

[0068] Furthermore, the liquid separation system 1B of the third embodiment differs from the first embodiment in that it discharges the heavy liquid MD (second liquid L2) of the heavy liquid layer HF2, which has been separated by sedimentation within the housing 5 of the filter section 50B, to the outside of the liquid separation system 1B through a discharge pipe 34B provided at the bottom of the housing 5B. By providing the discharge pipe 34B at the inner bottom of the housing 5 in this way, it becomes difficult for light liquid to mix with the heavy liquid discharged from inside the housing 5B.

[0069] As described above, the liquid separation system 1B, as shown in Figure 4, comprises a centrifuge 2 that separates the raw liquid US, which contains light liquid and heavy liquid, into a first liquid LF1 mainly composed of light liquid and a second liquid HF1 mainly composed of heavy liquid; a coalescer filter 3 to which the separated liquid SS2, consisting of the second liquid HF1, is supplied; and a housing 5B that houses the coalescer filter 3. The coalescer filter 3 captures and aggregates the minute light liquid remaining in the separated liquid SS2, causing it to grow into coarse droplets, thereby separating the heavy liquid from the separated liquid SS2. Due to the difference in specific gravity between the heavy liquid and the light liquid (coarse droplets), the coarse droplets float within the housing 5B, forming a light liquid layer LF2 mainly composed of light liquid and a heavy liquid layer HF2 mainly composed of heavy liquid within the housing 5B.

[0070] According to the liquid separation system 1B, the separated liquid SS2 (a liquid mainly consisting of heavy liquid and containing a small amount of light liquid) discharged from the centrifuge 2 can be further precisely separated into light liquid and heavy liquid.

[0071] Furthermore, as shown in Figure 4, the liquid separation system 1B further includes a return channel 33B that returns the first liquid L1 (liquid) constituting the light liquid layer LF2 separated by the coalescer filter 3 back to the stock supply pipe 22 that supplies the stock solution US to the centrifuge 2. The return channel 33B is connected to the upper part of the cylindrical body 51B or the upper flange 52B.

[0072] With this configuration, the liquid constituting the light liquid layer LF2 can be returned to the centrifuge 2. The light liquid LL in the light liquid layer LF2 is mixed with the stock liquid US in a coarser state, and as a result, it becomes included in the first liquid LF1 during the centrifugation process in the centrifuge 2.

[0073] [Fourth Embodiment] Next, referring to Figure 5, the liquid separation system 1C and liquid separation method according to the fourth embodiment will be explained, focusing on the differences from the liquid separation system 1A according to the second embodiment (see Figure 3). Figure 5 is a schematic diagram showing a liquid separation system 1C and a liquid separation method according to the fourth embodiment.

[0074] As shown in Figure 5, the liquid separation system 1C according to the fourth embodiment differs from the second embodiment in that the stock solution US containing light liquid and heavy liquid has a larger ratio of heavy liquid to light liquid than the stock solution US of the second practical embodiment.

[0075] Furthermore, the liquid separation system 1C of the fourth embodiment differs from the second embodiment in that it discharges the first liquid LF1 (a liquid mainly consisting of light liquid with a small amount of heavy liquid) separated from the raw liquid US by the centrifuge 2 to the outside of the liquid separation system 1B through the separated light liquid outlet pipe 26.

[0076] Furthermore, the liquid separation system 1C of the fourth embodiment differs from the second embodiment in that it supplies the second liquid HF1 (a liquid mainly consisting of heavy liquid and containing a small amount of light liquid) separated from the raw liquid US by the centrifuge 2 as the separated liquid SS2 to the inside of the coalescer filter 3 through the separated heavy liquid supply pipe 25.

[0077] Furthermore, the liquid separation system 1C of the fourth embodiment differs from the second embodiment in that it returns the light liquid LL of the light liquid layer LF2, which has been separated by flotation within the housing 5C of the filter section 50C, to the raw liquid supply pipe 22 upstream of the centrifuge 2 via the return channel 33C.

[0078] Furthermore, the liquid separation system 1C according to the fourth embodiment differs from the second embodiment in that it houses an oil-repellent filter 6 that repels oil. As shown in Figure 5, a coalescer filter 3 is provided hanging down from the lid (upper flange 52C) of the housing 5C, and an oil-repellent filter 6 is installed at the bottom (lower flange 53C) of the housing 5C. The coalescer filter 3 is positioned around the internal piping section 25-1 of the supply pipe (separation heavy liquid supply pipe 25) which is inserted into the interior of the housing 5C through the lid (upper flange 52C) of the housing 5C. The oil-repellent filter 6 is inserted into the interior of the housing 5C through the lid (upper flange 52C) of the housing 5C and is positioned around the internal piping section 34A-1 of the discharge pipe 34A which discharges the separated liquid from the oil-repellent filter 6. The return channel 33C is connected to the upper part of the cylindrical body 51C or the upper flange 52C.

[0079] According to the liquid separation system 1C, the oil-repellent filter 6 inside the housing 5C of the filter section 50C can remove oil and solids from the heavy liquid in the heavy liquid layer HF2 that has been separated by sedimentation. As a result, the purity of the heavy liquid discharged from the discharge pipe 34C of the housing 5C can be increased. Furthermore, since the housing 5C houses both the coalescer filter 3 and the oil-repellent filter 6 in a single housing 5C, the assembly man-hours and number of parts can be reduced compared to when the coalescer filter and oil-repellent filter are installed separately, thereby reducing costs.

[0080] According to the liquid separation system 1C, the light liquid LL separated by flotation can be returned as the first liquid L1 to the upstream side of the centrifuge 2 via the return channel 33C. The light liquid in the light liquid layer LF2 is mixed with the stock liquid US in a coarser state, and as a result, it becomes included in the first liquid LF1 during the centrifugation process in the centrifuge 2.

[0081] [Fifth Embodiment] Next, with reference to Figure 6, a liquid separation system and liquid separation method according to the fifth embodiment will be described. Figure 5 is a schematic diagram showing a liquid separation system and liquid separation method according to the fifth embodiment, and is a longitudinal cross-sectional view of the central part of the filter section 50D.

[0082] In the filter section 50A shown in Figure 3, the water-repellent filter 4 is positioned to the side of the coalescer filter 3. However, in this embodiment, as shown in Figure 5, it is preferable to arrange the water-repellent filter 4 and the coalescer filter 3 within a vertically elongated housing 5D, with the water-repellent filter 4 positioned above the coalescer filter 3.

[0083] The separation light liquid supply pipe 23 is inserted into the coalescer filter 3 by passing through the lower flange 53D of the housing 5D. The upper open end of the separation light liquid supply pipe 23 is closed with a plug member 231, and the separation light liquid supply pipe 23 and the coalescer filter 3 are fixed by screwing the plug member 231 and the filter support member 31A with a bolt 232. Multiple through holes 23a are formed in the internal piping section 23-1 of the separation light liquid supply pipe 23 that is inserted into the coalescer filter 3, and the separation liquid SS1 supplied by the separation light liquid supply pipe 23 is discharged through the through holes 23a from inside the pipe to the coalescer filter 3 outside the pipe. The coalescer filter 3 comprises a cylindrical filter material 30, filter support members 31 (31A, 31B) positioned above and below it, and packings 32 (32A, 32B) interposed between the end face of the filter material 30 and the filter support members 31 (31A, 31B). The filter material 30 is held between the filter support members 31 (31A, 31B) positioned above and below it.

[0084] The housing 5D comprises a vertically elongated cylindrical body 51D, an upper flange 52D provided to close the upper opening of the cylindrical body 51D, and a lower flange 53D provided to close the lower opening of the cylindrical body 51D. The cylindrical body 51D houses a coalescer filter 3 and a water-repellent filter 4. The coalescer filter 3 is housed in the lower part of the cylindrical body 51D, and the water-repellent filter 4 is housed in the upper part of the cylindrical body 51D. The exhaust pipe 34 is inserted into the upper flange 52D. The lower flange 53D has a separation light liquid supply pipe 23 and a return channel 33 inserted into it.

[0085] The discharge pipe 34 is inserted into the water-repellent filter 4, passing through the upper flange 52D of the housing 5D. The lower open end of the discharge pipe 34 is closed with a plug member 341, and the discharge pipe 34 and the water-repellent filter 4 are fixed by screwing the plug member 341 and the filter support member 31B together with a bolt 342. The light liquid LL in the light liquid layer LF2 inside the housing 5D that has passed through the coalescer filter 3 passes through the water-repellent filter 4 and is discharged from the discharge pipe 34 through a through hole 34a provided in the internal piping section 34-1 inside the water-repellent filter 3 of the discharge pipe 34.

[0086] The water-repellent filter 4 comprises a cylindrical filter material 40, filter support members 41 (41A, 41B) positioned above and below it, and packings 42 (42A, 42B) interposed between the end face of the filter material 40 and the filter support members 41 (41A, 41B), respectively. The filter material 40 is held between the filter support members 41 (41A, 41B) positioned above and below it. The discharge pipe 34 and the water-repellent filter 4 are fixed together by screwing a bolt 342, which passes through the filter support member 41B, into a stopper member 341 of the discharge pipe 34, which is inserted into the water-repellent filter 4.

[0087] As described above, the filter section 50D shown in Figure 6 comprises a coalescer filter 3 and a water-repellent filter 4 positioned above the liquid flow of the coalescer filter 3 within the housing 5D. The coalescer filter 3 is positioned around a supply pipe (separation light liquid supply pipe 23) that penetrates the bottom (lower flange 53D) of the housing 5D and is inserted into the interior of the housing 5D. The water-repellent filter 4 is positioned around a discharge pipe 34 that penetrates the lid (upper flange 52D) of the housing 5D and is inserted into the interior of the housing 5D, and discharges the separated liquid from the water-repellent filter 4. The return flow path 33 is connected to the bottom (lower flange 53D) of the housing 5D.

[0088] With this configuration, as shown in Figure 6, the housing 5D can be made long in the vertical direction. Therefore, the housing 5D can reduce the area it occupies when installed, and thus the entire filter unit 50D can be made smaller.

[0089] [Sixth Embodiment] Next, with reference to Figure 7, a liquid separation system and liquid separation method according to the sixth embodiment will be described. Figure 7 is a schematic diagram showing a liquid separation system and liquid separation method according to the sixth embodiment, and is a longitudinal cross-sectional view of the central part of the filter section 50E.

[0090] As shown in Figure 7, the filter section 50E may have the oil-repellent filter 6 positioned below the liquid flow of the coalescer filter 3 inside the housing 5E.

[0091] The separation light liquid supply pipe 23E is inserted into the coalescer filter 3 by passing through the upper flange 52E. The lower open end of the separation light liquid supply pipe 23E is closed with a plug member 231, and the separation light liquid supply pipe 23E and the coalescer filter 3 are fixed by screwing the plug member 231 and the filter support member 31B with a bolt 232. Multiple through holes 23Ea are formed in the internal piping section 23E-1 of the separation light liquid supply pipe 23E that is inserted into the coalescer filter 3, and the separation liquid SS2 supplied by the separation light liquid supply pipe 23E is discharged through the through holes 23Ea from inside the pipe to the coalescer filter 3 outside the pipe.

[0092] The housing 5E comprises a vertically elongated cylindrical body 51E, an upper flange 52E provided to close the upper opening of the cylindrical body 51E, and a lower flange 53E provided to close the lower opening of the cylindrical body 51E. The cylindrical body 51E houses a coalescer filter 3 and an oil-repellent filter 6. The coalescer filter 3 is housed in the upper part of the cylindrical body 51E, and the oil-repellent filter 6 is housed in the lower part of the cylindrical body 51E. The upper flange 52E has a separation light liquid supply pipe 23E and a return channel 33 inserted into it. The discharge pipe 34E is inserted into the lower flange 53E.

[0093] The discharge pipe 34E is inserted into the oil-repellent filter 6 by passing through the lower flange 53E. The upper open end of the discharge pipe 34E is closed with a plug member 342, and the discharge pipe 34E and the oil-repellent filter 6 are fixed by screwing the plug member 342 and the filter support member 61A with bolts 342. Multiple through holes 34Ea are formed in the internal piping section 23E-1 of the portion of the discharge pipe 34E that is inserted into the oil-repellent filter 6, and the heavy liquid MD in the heavy liquid layer HF2 inside the housing 5D that has passed through the coalescer filter 3 is discharged from the discharge pipe 34 through the through holes 34Ea after passing through the water-repellent filter 6.

[0094] The oil-repellent filter 6 comprises a cylindrical filter material 60, filter support members 61 (61A, 61B) positioned above and below it, and packings 62 (62A, 62B) interposed between the end face of the filter material 60 and the filter support members 61 (61A, 61B), respectively. The filter material 60 is held between the filter support members 61 (61A, 61B) positioned above and below it. The discharge pipe 34E and the oil-repellent filter 6 are fixed by screwing a bolt 342, which passes through the filter support member 61A, into a stopper member 341 of the discharge pipe 34E, which is inserted into the oil-repellent filter 6.

[0095] As shown in Figure 7, the filter section 50E comprises a coalescer filter 3 and an oil-repellent filter 6 positioned above the liquid flow of the coalescer filter 3 and having oil-repellent properties, all within the housing 5E. The coalescer filter 3 is positioned around a supply pipe (separation light liquid supply pipe 23E) that is inserted into the housing 5E through the lid portion (upper flange 52E) of the housing 5E. The oil-repellent filter 6 is inserted into the housing 5E through the lid portion (lower flange 53E) of the housing 5E and is positioned around a discharge pipe 34E that discharges the separated liquid from the oil-repellent filter 6. The return flow path 33E is connected to the bottom of the housing 5E.

[0096] With this configuration, as shown in Figure 7, the housing 5E of the filter unit 50E can be made long in the vertical direction by arranging the oil-repellent filter 6 inside the housing 5E below the coalescer filter 3. Therefore, the housing 5E can occupy a smaller installation area, and thus the entire filter unit 50E can be made smaller.

[0097] [Differentiation] It should be noted that the present invention is not limited to the first to sixth embodiments described above, and various modifications and changes are possible within the scope of its technical concept. Naturally, the present invention also extends to such modified and altered inventions. For example, in the liquid separation systems 1, 1A, 1B, and 1C of the first to fourth embodiments, the case where one centrifuge 2 is used was described, but multiple centrifuges 2 may be installed and the raw liquid US may be centrifuged multiple times.

[0098] Furthermore, in the second embodiment shown in Figure 3, a case was described in which one coalescer filter 3 and one water-repellent filter 4 are arranged laterally at appropriate intervals within the housing 5A, but multiple units of either one of the filters may be provided.

[0099] Furthermore, the number of coalescer filters 3 and water-repellent filters 4 shown in Figure 3 may be increased as appropriate to match the size of the housings 5A and 5C if the housings 5A and 5C are large. If the number of coalescer filters 3 is increased, the separation light liquid supply pipes 23 and separation heavy liquid supply pipes 25 shown in Figures 2 and 4 can be made into multiple pipes, or the downstream side can be branched, and coalescer filters 3 can be installed in each of the downstream sections.

[0100] Furthermore, the housing 5 may also be equipped with a bubble generating device for generating bubbles in the separated liquids SS1 and SS2 supplied from the centrifuge 2, and a filter for removing the bubbles generated by the bubble generating device. In this way, oil and other substances contained in the separated liquids SS1 and SS2 can be separated. [Explanation of Symbols]

[0101] 1,1A,1B,1C Liquid Separation System 2. Centrifugal separator 3 Coalescer filter 4. Water-repellent filter 5, 5A, 5B, 5C, 5D, 5E enclosure 6. Oil-repellent filter 23,23D Separated light liquid supply pipe (supply pipe) 25 Separated heavy liquid supply pipe (supply pipe) 33, 33B, 33C, 33E Return channel 34,34A,34B,34D,34E Discharge pipe 50, 50A, 50B, 50C, 50D, 50E Filter section 51,51A,51B,51C,51D,51E Cylindrical body 52, 52A, 52B, 52C, 52D, 52E Upper flange (cover) 53, 53A, 53B, 53C, 53D, 53E Lower flange (bottom) HF1 Second liquid HF2 heavy liquid layer LF1 First liquid LF2 light liquid layer SS1 separation liquid US stock solution

Claims

1. A centrifuge that separates a stock solution containing a light liquid and a heavy liquid into a first liquid mainly composed of the light liquid and a second liquid mainly composed of the heavy liquid, A coalescer filter to which the separation liquid consisting of the second liquid is supplied, A housing for the aforementioned coalescer filter, Equipped with, The coalescer filter captures and aggregates the minute light liquid remaining in the separated liquid, causing it to grow into coarser droplets. As the coarse-grained droplets float within the housing due to the difference in specific gravity with the heavy liquid, a light liquid layer mainly composed of the light liquid and a heavy liquid layer mainly composed of the heavy liquid are formed within the housing. Liquid separation system.

2. The present invention further comprises a return channel for returning the liquid constituting the light liquid layer separated by the coalescer filter back to the stock supply pipe that supplies the stock to the centrifuge. The liquid separation system according to claim 1.

3. Inside the housing, The system comprises the aforementioned coalescer filter and an oil-repellent filter disposed below the coalescer filter and having oil-repellent properties. The coalescer filter is positioned around the supply pipe that penetrates the lid of the housing and is inserted into the interior of the housing, The oil-repellent filter is inserted into the interior of the housing by penetrating the bottom of the housing, and is positioned around the discharge pipe that discharges the liquid separated by the oil-repellent filter, and The return channel is connected to the top of the housing. The liquid separation system according to claim 2.

4. Inside the housing, The system comprises the aforementioned coalescer filter and an oil-repellent filter disposed to the side of the coalescer filter and having oil-repellent properties. The coalescer filter is positioned around the supply pipe that penetrates the lid of the housing and is inserted into the interior of the housing, The oil-repellent filter is inserted into the interior of the housing by penetrating the lid of the housing, and is positioned around the discharge pipe that discharges the separated liquid from the oil-repellent filter, and The return channel is connected to the housing. The liquid separation system according to claim 2.

5. Using the liquid separation system described in Claim 1, The first step involves supplying a stock solution containing heavy liquid and light liquid to a centrifuge and separating it into a first liquid mainly composed of the light liquid and a second liquid mainly composed of the heavy liquid. A second step involves supplying a separation solution consisting of the first liquid or the second liquid to a coalescer filter. A third step involves growing the minute heavy liquid or minute light liquid remaining in the separated liquid into coarse droplets, A fourth step involves separating the coarsely sized droplets into a heavy liquid layer mainly composed of the heavy liquid and a light liquid layer mainly composed of the light liquid by allowing them to settle or float. including, Liquid separation method.

6. A fifth step further comprising returning the liquid constituting the heavy liquid layer or the liquid constituting the light liquid layer separated by the coalescer filter back to the original liquid, The liquid separation method according to claim 5.

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