Vertical centrifugal separator, method for operating vertical centrifugal separator, and concentrated liquid recovery device using vertical centrifugal separator

Abstract

The present invention addresses the problem of providing a vertical centrifugal separator which is neither nozzle discharge nor valve discharge, suppresses the rupture of microbial cells, is capable of acquiring living microorganisms as a concentrated liquid of a heavy liquid, is capable of reducing the generation of contamination in a machine body, and is capable of continuously supplying a stock liquid containing microorganisms and intermittently taking out a high-concentration microbial concentrated liquid stored on a side of the heavy liquid without annihilation. The problem is solved by a vertical centrifugal separator 1 for continuously supplying a stock liquid containing microorganisms and separating the stock liquid into a heavy liquid and a light liquid, the vertical centrifugal separator including a structure in which a concentrated liquid of microorganisms is intermittently obtained from a side of the heavy liquid discharged via a heavy liquid impeller 22 facing a heavy liquid chamber 21, and having a structure in which replacement water for replacing a part or the whole of the heavy liquid in the heavy liquid chamber 21 can be injected into the heavy liquid chamber 21.

Description

Vertical centrifuge, operating method of vertical centrifuge, and concentrated liquid recovery device using vertical centrifuge 【0009】 , 【0008】 , , 【0007】 , , 【0001】 The present invention relates to a vertical centrifuge and an operating method of the vertical centrifuge. Specifically, it relates to a vertical centrifuge and an operating method of the vertical centrifuge that can continuously supply a stock solution containing microorganisms and intermittently extract a high-concentration microbial concentrated liquid stored on the heavy liquid side without killing it. 【0002】 Patent Document 1 discloses a technique for separating a liquid mixture of yeast and beer into a yeast concentrated liquid and clarified beer, taking out the beer as a product from the light liquid phase, and taking out the yeast concentrated liquid from the heavy liquid phase. However, Patent Document 1 aims to obtain clarified beer, and it is stated that most of the cells leaving the centrifuge by intermittent discharge of the heavy-phase yeast concentrated liquid are dead, and it does not consider obtaining the heavy-phase yeast concentrated liquid obtained by intermittent discharge as a product. 【0003】 Japanese Patent No. 7440624 【0004】 Conventionally, when concentrating microorganisms using a vertical centrifuge, it is generally performed by nozzle discharge or valve discharge. 【0005】 In nozzle discharge, the raw material is suitable for relatively high-concentration ones, but nozzle blockage and unstable concentration magnification often occur. 【0006】 In valve discharge, it can be applied to raw materials with a wide range of concentrations, but cell rupture and contamination inside the machine are likely to occur. 【0007】 The reason why contamination inside the machine is likely to occur is that after the concentrated liquid is discharged from the rotating body, the concentrated liquid adheres between the rotating body cover and the rotating body and dries, but when it dries, the contamination cannot be removed only by washing with water. 【0008】 In addition, when cell rupture occurs, the components inside the cells are released into the liquid, and by being released, the concentrated liquid is likely to rot or there is a risk that a concentrated liquid with excellent commercial value cannot be recovered. For this reason, a concentration technique that suppresses the rupture of microbial cells is required. 【0009】Therefore, the object of the present invention is to provide a vertical centrifuge and a method for operating a vertical centrifuge that can suppress the rupture of microbial cells, obtain live microorganisms as a concentrated heavy liquid, reduce the generation of contamination inside the machine, and furthermore, continuously supply a raw liquid containing microorganisms and intermittently extract a highly concentrated microbial liquid stored on the heavy liquid side without killing the microorganisms. 【0010】 Furthermore, other problems of the present invention will become clear from the following description. 【0011】 The above problems are solved by the following inventions. 【0012】1. A vertical centrifuge for separating a raw liquid containing microorganisms into a heavy liquid and a light liquid by continuously supplying it, characterized in that it has a structure for intermittently obtaining a concentrated liquid of microorganisms from the heavy liquid side discharged via a heavy liquid impeller facing the heavy liquid chamber, and has a structure for injecting displacement water into the heavy liquid chamber to replace part or all of the heavy liquid in the heavy liquid chamber. 2. The vertical centrifuge according to 1, characterized in that the structure for injecting displacement water comprises a displacement water supply unit capable of supplying displacement water to the heavy liquid chamber, a supply channel is formed in the displacement water supply unit, and the supply channel is arranged toward the upper gap of the heavy liquid chamber. 3. The vertical centrifuge according to 1, characterized in that the structure for intermittently obtaining a concentrated liquid of microorganisms from the heavy liquid side is configured to intermittently obtain a concentrated liquid of microorganisms from the heavy liquid side by opening and closing a heavy liquid discharge valve provided on a discharge pipe connected to a heavy liquid impeller facing the heavy liquid chamber. 4. The vertical centrifuge according to claim 1, characterized in that the heavy liquid chamber is partitioned into a room shape by an upper partition, a side partition and a rear partition, a heavy liquid impeller for discharging the concentrated liquid in the heavy liquid chamber is disposed on the upper part of the rear partition without an adjustment plate, a heavy liquid channel is formed in the gap between a rotating body lid connected to the side partition and a water intake plate, allowing the concentrated liquid in the separation chamber to be sent to the heavy liquid chamber, and the water intake plate extends toward the bottom of the separation chamber, with a gap formed between the tip of the water intake plate and the bottom. 5. A method for operating a vertical centrifuge for continuously supplying a stock solution containing microorganisms to the vertical centrifuge to separate it into a heavy liquid and a light liquid, and intermittently taking out the concentrated liquid of microorganisms stored on the heavy liquid side, characterized in that displacement water is injected into the heavy liquid chamber before or after intermittently taking out the concentrated liquid of microorganisms from the heavy liquid side to replace part or all of the heavy liquid with water. 6. The method for operating a vertical centrifuge according to item 5, characterized in that, when intermittently removing the concentrated microbial solution stored on the heavy liquid side, a heavy liquid discharge valve provided on a heavy liquid discharge pipe connected to a heavy liquid impeller facing the heavy liquid chamber is closed, thereby storing the concentrated microbial solution on the heavy liquid side.7. A concentrated liquid recovery apparatus using a vertical centrifuge as described in any of 1 to 4 above, wherein a heavy liquid discharge pipe is connected to the outlet of the heavy liquid impeller for discharging the concentrated liquid from the heavy liquid chamber via the heavy liquid impeller, a three-way valve is provided in the heavy liquid discharge pipe, and the three-way valve is characterized in that it branches the concentrated liquid discharged from the heavy liquid impeller into a return channel for returning the concentrated liquid to the vertical centrifuge and into a recovery channel for recovering the concentrated liquid. 8. A concentrated liquid recovery apparatus using a vertical centrifugal separator as described in any of 1 to 4 above, wherein when the concentrated liquid discharged from the heavy liquid impeller is recovered via a heavy liquid discharge pipe, a three-way valve is provided in the heavy liquid discharge pipe, and the three-way valve is configured to branch into a waste channel for recovering the concentrated liquid discharged from the heavy liquid impeller for disposal and a recovery channel for recovering the concentrated liquid. 9. A concentrated liquid recovery apparatus using a vertical centrifuge as described in any of 1 to 4 above, wherein when the concentrated liquid discharged from the heavy liquid impeller is recovered via a heavy liquid discharge pipe, a recovery channel for recovering the concentrated liquid is connected to the heavy liquid discharge pipe, and a return channel for returning the concentrated liquid to the stock supply pipe for introducing the stock liquid into the vertical centrifuge is provided upstream of the recovery channel, and on / off valves are provided in the recovery channel and the return channel, respectively, and the apparatus is configured so that the concentrated liquid discharged from the heavy liquid impeller can be branched into either the recovery channel or the return channel. A concentrated liquid recovery apparatus using a vertical centrifugal separator as described in any of 1 to 4 above, wherein when the concentrated liquid discharged from the heavy liquid impeller is recovered via a heavy liquid discharge pipe, a recovery channel for recovering the concentrated liquid is connected to the heavy liquid discharge pipe, and a waste channel for recovering the liquid for disposal is provided upstream of the recovery channel, and on / off valves are provided in the recovery channel and the waste channel, respectively, and the apparatus is configured so that the concentrated liquid discharged from the heavy liquid impeller can be branched into either the recovery channel or the waste channel. 【0013】 According to the present invention, by suppressing the rupture of microbial cells, rather than using nozzle or valve discharge, it is possible to obtain live microorganisms as a concentrated heavy liquid, thereby reducing the generation of contamination inside the machine. 【0014】 Furthermore, according to the present invention, by injecting displacement water, it is possible to prevent the temperature inside the heavy liquid chamber from rising and reduce the death of microorganisms. Also, by replacing the concentrated liquid with water, the concentrated liquid does not enter the heavy liquid chamber, thus reducing the disruption of microorganisms caused by agitation by the heavy liquid impeller inside the heavy liquid chamber. 【0015】 Figure 1 shows a cross-sectional view of the rotating body illustrating the configuration of the main part of a vertical centrifugal separator. Figure 2 shows a cross-sectional view of the rotating body illustrating the state of water displacement by displacement water. Figure 3 shows a cross-sectional view of the rotating body illustrating the configuration of the main part of a conventional vertical centrifugal separator. Figure 4 shows an example of the configuration of the main part of a device for recovering concentrated liquid discharged from the vertical centrifugal separator shown in Figure 1. Figure 5 shows another example of a modified configuration of the main part of the vertical centrifugal separator shown in Figure 1. Figure 6 shows an example of an operating method for a concentrated liquid recovery device using the vertical centrifugal separator according to this embodiment. 【0016】 The present invention will be described below based on the embodiment shown in Figure 1. 【0017】 Figure 1 is a half-cross-sectional view of the rotating body showing the main components of a vertical centrifugal separator. The drawing shows the main components of the vertical centrifugal separator 1, and the right half of the rotating body is illustrated. 【0018】 The vertical centrifugal separator 1, using a separation plate, separates the stock solution supplied via the stock solution supply pipe 10 into a concentrated solution and a clarified solution, and discharges them. 【0019】 In the present invention, the stock solution may contain one or more of the following: microalgae (such as Chlorella, Spirulina, Nannochloropsis, and Chlamydomonas), microorganisms (such as Escherichia coli, Lactobacillus, and Bacillus subtilis), fungi (such as yeast and mold), animal cells, viruses, etc., or a combination of two or more of these. In the following description, stock solutions containing the microorganisms to be concentrated (e.g., cultured microorganisms) are given as examples. 【0020】The rotating body 11 that constitutes the vertical centrifugal separator 1 is formed by a rotating body lid 12 and a bottom 13. Inside the rotating body 11, there is a separation chamber 16 having a separation plate 14 and a water intake plate 15, and a guide tube 17 that evenly distributes the raw liquid from the rotating body inlet to the separation chamber 16. 【0021】 The stock solution containing the microorganisms to be concentrated, introduced into the separation chamber 16 via the guide tube 17 from the stock solution supply pipe 10, is centrifuged by the separation plate 14 into a light liquid (clarified liquid) PW and a heavy liquid (microbial concentrate: SS in the drawing) SW. This invention is effective even when the specific gravities of the light liquid (clarified liquid) PW and the heavy liquid SW are relatively close. 【0022】 The light liquid PW in the separation chamber 16 is guided by the guide tube 17 and sent to the light liquid chamber 18. The light liquid in the light liquid chamber 18 is discharged to the outside as clarified liquid via the discharge pipe 20 by the light liquid impeller 19. 【0023】 The heavy liquid SW in the separation chamber 16 passes through the heavy liquid channel 150 formed between the rotating body lid 12 and the water intake plate 15 and is sent to the heavy liquid chamber 21. The heavy liquid in the heavy liquid chamber 21 is then discharged via the heavy liquid discharge pipe 23 by the heavy liquid impeller 22, and the concentrated liquid can be obtained as a product. 【0024】 In the separation chamber 16, when the stock solution containing microorganisms is centrifuged, the heavy liquid SW accumulates in the separation chamber 16, and the light liquid PW (clarified liquid) forms a vertical interface IF between itself and the heavy liquid SW (concentrated liquid). 【0025】 As centrifugal separation progresses within the separation chamber 16, the concentrated liquid SW increases and moves toward the center of the separation chamber 16. Meanwhile, the light liquid PW overflows within the separation chamber 16 from the inner circumferential end surface of the water intake plate 15 along the outer circumference of the guide cylinder 17 toward the light liquid impeller 19. 【0026】 The light liquid impeller 19 faces the light liquid chamber 18 formed at the upper end of the water intake plate 15 and discharges the light liquid PW (clarified liquid) that overflows from the separation chamber 16 and accumulates in the light liquid chamber 18. 【0027】The heavy liquid impeller 22 is positioned to face the heavy liquid chamber 21 formed at the upper end of the rotating body cover 12, and discharges the heavy liquid SW that is sent into the heavy liquid chamber 21 from the heavy liquid flow path 150 formed in the rotating body cover 12 and the water intake plate 15. 【0028】 In this invention, a heavy liquid discharge pipe 23 is connected to a heavy liquid impeller 22 facing a heavy liquid chamber 21, and the concentrated liquid is discharged from the heavy liquid discharge pipe 23. 【0029】 A heavy liquid discharge valve 26 is provided in the heavy liquid discharge pipe 23 connected to the heavy liquid impeller 22 in order to intermittently extract the concentrated liquid from the heavy liquid side. In this embodiment, it is preferable that a pressure gauge 27 is provided to measure the back pressure generated by the heavy liquid discharge valve 26. 【0030】 Therefore, a characteristic of this invention is that while the supply of the stock solution is continuous, the extraction of the concentrated solution is intermittent. In this invention, discontinuous concentration operation (batch operation) is suitable for extracting concentrated microorganisms from the concentrated solution, and by incorporating water displacement into the extraction of the concentrated solution, the microorganisms can be extracted without being killed. 【0031】 In the batch operation according to the present invention, while the stock solution is being supplied from the stock solution supply pipe 10, the heavy liquid discharge valve 26 is closed to stop the discharge of the concentrated liquid. With the heavy liquid discharge valve 26 closed and the discharge of the concentrated liquid stopped, the stock solution containing microorganisms is separated into a clarified liquid and a concentrated liquid by the action of the separation plate 14, and the concentrated liquid accumulates in the separation chamber 16. 【0032】 Furthermore, concentrated liquid accumulates in the heavy liquid chamber 21, and also in the flow path that supplies the concentrated liquid to the heavy liquid chamber 21. 【0033】 Since the heavy liquid impeller 22 is fixed inside the heavy liquid chamber 21, contact occurs between the heavy liquid impeller 22 and the concentrated liquid inside the heavy liquid chamber 21, causing friction and resulting in a temperature rise of the concentrated liquid inside the heavy liquid chamber 21. This temperature rise may kill the microorganisms. 【0034】Furthermore, contact between the heavy liquid impeller 22 and the concentrated liquid in the heavy liquid chamber 21 can cause shearing, which may destroy (shatter) the cell walls of microorganisms in the concentrated liquid in the heavy liquid chamber 21, potentially leading to the death of the microorganisms. 【0035】 From the perspective of producing a concentrated microbial solution, batch operation (discontinuous concentration) was performed to obtain the desired concentrate. However, as described above, as the concentration time progressed, the temperature rise due to friction, which is a problem specific to concentration, caused the death of microorganisms, and the shearing of the impeller caused the microorganisms to be crushed and killed. Water displacement in the heavy liquid chamber 21 solves this problem. 【0036】 The water displacement apparatus in the present invention can employ a structure that allows displacement water to be injected into the heavy liquid chamber 21 from outside the heavy liquid chamber 21, thereby replacing part or all of the heavy liquid in the heavy liquid chamber 21. 【0037】 A structure capable of injecting displacement water is preferably configured to include a displacement water supply unit 24B capable of supplying displacement water to the heavy liquid chamber 21, with the displacement water being supplied toward the heavy liquid chamber 21 through an upper gap 24A. Alternatively, instead of the displacement water supply unit 24B, a pipe 24 may be inserted into the heavy liquid chamber 21 through the upper gap 24A of the heavy liquid chamber 21, and the outlet of the displacement water of the pipe 24 may be immersed in the concentrated liquid. In this embodiment, an on / off valve 25 can be provided on the pipe 24. 【0038】 By injecting displacement water into the heavy liquid chamber 21, it is possible to prevent the temperature inside the heavy liquid chamber 21 from rising. Furthermore, by injecting displacement water into the heavy liquid chamber 21, the concentrated liquid is discharged from the heavy liquid chamber 21, thereby reducing the disruption of microorganisms caused by agitation by the heavy liquid impeller 22 inside the heavy liquid chamber 21. 【0039】 The following describes, with reference to Figure 1 and based on Figure 2, the process by which displacement water is supplied to the heavy liquid chamber 21 via piping 24, thereby replacing the concentrated liquid in the heavy liquid chamber 21 with water. 【0040】The heavy liquid chamber 21 is divided into compartments by an upper partition 210, a side partition 211, and a rear partition 212 (which is continuous with the rotating body lid 12), with the raw liquid supply pipe 10 side being open. The vertical centrifuge 1 continues to rotate, and when the vertical liquid level of the concentrated liquid in the heavy liquid chamber 21 reaches L1 due to centrifugal force, the heavy liquid discharge valve 26 is closed to perform water replacement. 【0041】 The displacement water from the piping 24 can be supplied through the upper gap 24A formed in the heavy liquid chamber 21. For example, displacement water such as tap water is supplied to the displacement water supply unit 24B, and the displacement water is introduced from below the displacement water supply unit 24B toward the upper gap 24A and supplied into the heavy liquid chamber 21. In this embodiment, tap water is used as an example of displacement water, but a portion of the centrifuged clarified liquid may also be used as displacement water. 【0042】 The displacement water supply unit 24B has, for example, an inlet 240B for introducing displacement water, a storage unit 241B for storing displacement water from the inlet 240B, a supply channel 242B formed below the storage unit 241B, and is configured to supply displacement water from the outlet of the supply channel 242B to the upper gap 24A formed in the heavy liquid chamber 21. The displacement water supply unit 24B is not limited to this, and any configuration that can supply displacement water to the upper gap 24A is acceptable. 【0043】 When the heavy liquid discharge valve 26 is closed and water replacement is performed, and replacement water is supplied, centrifugal force is acting inside the heavy liquid chamber 21. Because the concentrated liquid has a higher specific gravity than the replacement water, it moves circumferentially away from the stock liquid supply pipe 10 side (central axis side) where the stock liquid is supplied, and the concentrated liquid interface moves to L2. As the supply of replacement water continues, the concentrated liquid interface becomes L3, and the concentrated liquid inside the heavy liquid chamber 21 is completely replaced by the replacement water. In the illustrated example, the amount of replacement water supplied is about the same as the capacity of the heavy liquid chamber 21, but it is not particularly limited. It is preferable that the heavy liquid chamber 21 is filled with replacement water. 【0044】Under the condition that the centrifugal force is acting in the heavy liquid chamber 21 as described above, a vertical interface formed by the replacement water and the concentrated liquid is formed separately from the vertical interface formed by the clarified liquid and the concentrated liquid in the separation chamber 16, so that the concentrated liquid in the heavy liquid chamber 21 can be replaced with water. 【0045】 Since the stock solution is being supplied even during this water replacement, the separation of the clarified liquid and the concentrated liquid by the centrifuge 1 continues. How long this water-replaced state can be maintained depends on the increase of the concentrated liquid in the separation chamber 16. For example, in order to prevent the concentrated liquid from leaking out from the clarified liquid side, the heavy liquid discharge valve 26 may be opened at a time determined by a timer to discharge the concentrated liquid. 【0046】 When the heavy liquid discharge valve 26 is opened, the concentrated liquid accumulated by batch operation can be taken out as a product through the heavy liquid discharge pipe 23. 【0047】 When taking out this product, after opening the heavy liquid discharge valve 26, the initial waste portion is a portion where the influence of the replacement water appears and the concentration is low, so it is preferably not used as a product as the first waste. Also, the concentrated liquid after obtaining a predetermined amount as a product preferably is not used as a product because the re-concentration becomes low. 【0048】 According to experimental findings, in the centrifuge of model "SJ10F Sanitary", the amount of the first waste (the amount of the first waste area) is 100 to 200 mL, the amount of the concentrated liquid that can be obtained as a product (the amount of the product area) is 600 mL to 900 mL, and the portion exceeding 900 mL is a portion with a low concentration that does not become a product (the portion of the area that does not become the last product). 【0049】 In the present invention, when the accumulated concentrated liquid runs out, the heavy liquid discharge valve 26 is closed again, and the concentration of microorganisms is performed by batch operation, stored, and at that time, the water replacement of the present invention is performed, and then the concentrated liquid as a product is taken out. When the heavy liquid discharge valve 26 is opened and the discharge of the concentrated liquid is started, the integrated flow rate by the flow meter provided in the heavy liquid discharge pipe 23 in advance may be detected, and when a predetermined integrated flow rate is reached, the heavy liquid discharge valve 26 may be controlled to close. In the present embodiment, among the opening and closing controls of the heavy liquid discharge valve 26, the opening control can be performed by timer control, and the closing control can be performed by integrated flow rate control. 【0050】 In the present invention, the start time of water displacement may be at the start of concentration in the batch operation in the above embodiment, or it may be at the start of the second or subsequent batch operation after the first batch operation has finished. 【0051】 The end time for water displacement can be anytime between the clear liquid (light liquid) and the discharge of the concentrated liquid, and it is preferable to set this using a timer. The start time for water displacement is approximately the same as the closing of the heavy liquid discharge valve, so it is also possible to control the process by detecting the cumulative flow rate using a flow meter installed in the heavy liquid discharge pipe 23. 【0052】 By performing the water displacement described above, the temperature rise of the heavy liquid chamber 21 can be suppressed, preventing the death of microorganisms, and also preventing the death of microorganisms due to shear caused by friction originating from the heavy liquid impeller 22. 【0053】 In this embodiment, the heavy liquid impeller 22, which discharges the concentrated heavy liquid from the heavy liquid chamber 21, is installed above the rear partition material 212 without providing an adjustment plate. That is, as shown in the figure, there is no adjustment plate between the heavy liquid impeller 22 and the rear partition material 212; nothing is provided between them. 【0054】 Conventionally, the adjustment plate 112 has been used to maintain the vertical separation interface between the light liquid and heavy liquid within the rotating body within a certain range (see Figure 3). When microorganisms were concentrated using the centrifuge 100 installed in the heavy liquid chamber 113, it was thought that cell disruption of microorganisms occurred due to shearing by the heavy liquid impeller 116. Furthermore, given the unique nature of the target of concentration being microorganisms, and the structure of the heavy liquid chamber 113 in which the adjustment plate 112 was located above the rear partition material 115 below the heavy liquid impeller 116, the inventors recognized that microorganisms could not pass through the adjustment plate 112 by centrifugation, and that the concentrated liquid could not be discharged to the outside. After diligent research, the inventors arrived at the present invention. 【0055】With the addition of the adjustment plate 112, if the adjustment plate 112 is long (extending towards the central axis), the concentrated liquid is discharged from the heavy liquid side in a diluted state and only in small quantities. If the adjustment plate 112 is shortened (moving away from the central axis), the concentration is somewhat improved and the quantity increases slightly compared to when the adjustment plate 112 is long, but it is not possible to obtain a satisfactory amount. 【0056】 In contrast, as shown in Figures 1 and 2, when no adjustment plate is used, the microbial concentrate is sent into the heavy liquid chamber 21 without pressure loss due to the adjustment plate, and the pressure of the concentrate does not decrease, and it is discharged from the heavy liquid impeller 22 by centrifugal force. 【0057】 Based on these findings, after conducting various studies on the effect of the control plate on the extraction of concentrated microorganisms, we found that removing the control plate increased the degree of concentration of the microorganisms, allowing us to recover highly valuable concentrated microorganisms. 【0058】 According to the rotating body structure of this embodiment, when performing batch operation (discontinuous concentration) to obtain the desired concentrate, the absence of a control plate allows for smooth extraction of the concentrate from the heavy liquid impeller during the process of removing the concentrate. 【0059】 Furthermore, as shown in Figures 1 and 2, in the rotating body structure of this embodiment, the rotating body lid 12 is connected to the side partition member 211. The gap between the rotating body lid 12 connected to the side partition member 211 and the water intake plate 15 forms a heavy liquid flow path 150 that allows the heavy liquid (concentrated liquid) in the separation chamber 16 to be delivered to the heavy liquid chamber 21. 【0060】 In this embodiment, when the heavy liquid discharge valve 26 is opened, the concentrated liquid accumulated by batch operation can be removed as a product via the heavy liquid discharge pipe 23 after passing through the heavy liquid flow path 150 and the heavy liquid chamber 21. 【0061】 Furthermore, in a conventional vertical centrifugal separator 100 as shown in Figure 3, the water intake plate 106 extends to near the center in the width direction of the rotating body cover 103, but does not extend to near the bottom of the rotating body cover 103. 【0062】In contrast, the present embodiment shown in Figures 1 and 2 is characterized in that the water intake plate 15 extends to the vicinity of the lower part of the rotating body lid 12. Because the water intake plate 15 is long, the heavy liquid flow path 150 extends to the area in the separation chamber 16 where the concentrated liquid is concentrated, thus making it easier to extract the concentrated liquid. 【0063】 In this embodiment, the upper partition member 210 of the heavy liquid chamber 21 is formed by extending it toward the central axis side of the rotating body (the raw liquid piping side), thereby reducing the circumference diameter of the circumferential upper gap 24A formed between the tip of the upper partition member 210 and the central axis. That is, in this embodiment, the tip 210a of the upper partition member 210 of the heavy liquid chamber 21 is formed by extending it toward the central axis side of the rotating body. The upper gap 24A formed by the tip 210a is formed circumferentially around the central axis and forms a gap between the tip 210a and the central axis. The circumference diameter of the circumferential upper gap 24A formed at the top of the heavy liquid chamber 21 (the circumference diameter formed by the tip 210a) is reduced by the amount that the tip 210a is formed by extending it toward the central axis side of the rotating body. This is because, by eliminating the adjustment plate, the vertical interface formed by the liquid in the heavy liquid chamber tends to shift toward the central axis side. Therefore, by reducing the diameter of the upper gap 24A, even if liquid splashes occur at the vertical interface formed by the liquid in the heavy liquid chamber, that interface becomes further away from the upper gap 24A, thus preventing leakage from the upper gap 24A. 【0064】 Here, the upper partition material 210 in Figures 1 and 2 will be further explained in comparison with the upper partition material 114 in the rotating body half-section diagram showing the main components of a conventional vertical centrifugal separator, as shown in Figure 3. 【0065】 In Figure 3, the central axis-side tip 114a of the upper partition member 114 is positioned at a distance equal to or slightly closer to the central axis than the inner diameter of the separation plate 105, which is indicated by the dashed line. Conventionally, the central axis-side tip 114a of the upper partition member 114 is positioned at a distance of approximately 95% of the distance from the central axis to the inner diameter of the separation plate 105, where 100% is the distance from the central axis. 【0066】The upper partition member 114 is a component that rotates during the operation of the centrifugal separator. The central axis side, which forms the supply and discharge passages for the liquid including the heavy liquid impeller 116, the raw liquid supply pipe, and the light liquid impeller, is made of a fixed, non-rotating component and cannot be brought into contact with it, so it was necessary to form an upper gap 120. The raw liquid being handled is, for example, fuel oil. When fuel oil is centrifuged, solid components are discharged, oil is discharged from the light liquid side and water from the heavy liquid side. When fuel oil is centrifuged, the specific gravity of water is greater than that of oil, so the water interface formed in the heavy liquid chamber is formed outward compared to the oil interface formed in the light liquid chamber. Therefore, there was no need to narrow the upper gap formed at the top of the heavy liquid chamber. 【0067】 If the interface of the heavy liquid accumulated in the heavy liquid chamber 113 were to leak out through the upper gap 120, there was a risk of leakage to the outside. However, since the leak from the upper gap 120 was water, it did not pose a major problem. 【0068】 However, in this embodiment shown in Figures 1 and 2, there is almost no difference in specific gravity between the concentrated liquid and the clarified liquid separated in the stock solution, and the concentrated liquid that becomes the product is discharged from the heavy liquid side. Since there is no difference in specific gravity between the separated clarified liquid (light liquid) and the concentrated liquid (heavy liquid), there is almost no difference in the interface formed between the light liquid chamber 18 and the heavy liquid chamber 21. For this reason, it is preferable that the tip portion 210a of the upper partition material 210 in Figures 1 and 2 is positioned significantly closer to the central axis than the inner diameter of the separation plate 14 shown by the dashed line. Specifically, it is preferable that it is about 85% or less of the distance from the central axis to the inner diameter of the separation plate. As a result, the diameter of the upper gap 24A is reduced, and leakage of concentrated liquid from the upper gap 24A can be reduced. 【0069】 In the present invention, a vertical centrifuge is used to continuously supply a stock solution containing microorganisms to a vertical centrifuge to separate it into heavy liquid and light liquid, and to intermittently remove the concentrated microbial solution stored in the heavy liquid side. The invention provides a method for operating the vertical centrifuge in which displacement water is injected into the heavy liquid chamber before or after intermittently removing the concentrated microbial solution from the heavy liquid side to replace part or all of the heavy liquid with water. 【0070】This allows for the injection of displacement water to prevent temperature rise in the heavy liquid chamber and reduce the death of microorganisms. Furthermore, by replacing the concentrated liquid with water, the concentrated liquid is not present in the heavy liquid chamber, thus reducing the disruption of microorganisms caused by agitation by the heavy liquid impeller inside the chamber. 【0071】 In this embodiment, it is preferable to use a vertical centrifuge capable of intermittent valve discharge. In the illustrated example, the bottom portion 13 located below the rotating body cover 12 is not provided as a rotary valve capable of valve discharge, but it may be provided. In this embodiment, since the microorganisms are removed from the heavy liquid chamber 21 side without being discharged by the bottom portion 13, which is a rotary valve, valve discharge by the rotary valve is performed only in cases such as maintenance such as cleaning the centrifuge or in the case of an emergency stop of the centrifuge, and it is preferable not to perform valve discharge of the concentrated liquid using the rotary valve during normal operation. 【0072】 An example of a concentrated liquid recovery apparatus using a vertical centrifuge of this embodiment will be described with reference to Figures 4 and 5. Figure 4 is a half cross-sectional view of a rotating body showing an example of the configuration of the main part of the concentrated liquid recovery apparatus discharged from the vertical centrifuge shown in Figure 1, and Figure 5 is a half cross-sectional view of a rotating body showing another example of a modified configuration of the main part of the vertical centrifuge shown in Figure 1. Reference numerals in the figures that are the same as in Figure 1 will not be explained. 【0073】 In this embodiment, as shown in Figure 4, it is preferable to provide a three-way valve 28 at any position in the heavy liquid discharge pipe 23. 【0074】 The concentrated liquid is introduced from the heavy liquid impeller 22 through the heavy liquid discharge pipe 23 to the inlet of the three-way valve 28. One outlet of the three-way valve 28 is connected to the recovery channel 29a for the concentrated liquid that will become the product, and the other outlet is connected to the return channel 29b which returns the concentrated liquid to the stock liquid that is introduced into the stock liquid supply pipe 10. By returning the concentrated liquid to the stock liquid supply pipe 10 via the return channel 29b, if the degree of concentration is too low to meet the quality standards for the product, it can be mixed with the stock liquid again and concentrated again in the centrifuge. 【0075】As shown in Figure 5, instead of the return channel 29b that returns the concentrate to the stock liquid and is connected to the other outlet of the three-way valve 28 in Figure 4, it may be connected to a waste channel 29c for separate recovery of the discharged concentrate, for example, for disposal. The waste channel 29c is preferably used to dispose of concentrates with a low degree of concentration that do not meet the quality standards for the product. As shown in Figure 5, if the concentrate has a significant impact on the properties of the stock liquid, it is better to dispose of it to ensure stable recovery of the concentrate that will become the product. 【0076】 The three-way valve 28 shown in Figures 4 and 5 is preferably configured to automatically switch the outlet direction. For example, it is preferable to perform automatic control such as switching based on the color of the concentrated liquid, switching by a timer, or switching based on the cumulative flow rate of a flow meter. In this embodiment, as described above, it is preferable to perform this control separately from the opening and closing control of the on-off valve 25 associated with water addition and the control of the heavy liquid discharge valve 26 associated with the discharge of the concentrated liquid. The start timing of the switching control is preferably when the heavy liquid discharge valve 26 is opened. For example, switching control based on the color of the concentrated liquid can be performed by making a part of the heavy liquid discharge pipe 23 transparent, installing a measuring instrument that can measure a color (not shown), and switching the outlet direction of the three-way valve 28 according to the color information. 【0077】 Furthermore, the timer-based switching control can, for example, use the time the heavy liquid discharge valve 26 is open as a reference. Until a predetermined time has elapsed from the reference point, the three-way valve 28 opens the return passage 29b and closes the recovery passage 29a, and after the predetermined time has elapsed, it closes the return passage 29b and opens the recovery passage 29a, thereby switching the outlet direction of the three-way valve 28. 【0078】 Furthermore, the switching control based on the cumulative flow rate of the flow meter is performed, for example, by installing a flow meter downstream of the heavy liquid discharge valve 26 of the heavy liquid discharge pipe 23 and upstream of the three-way valve 28, and measuring the cumulative flow rate of the concentrated liquid flowing through the flow meter per unit time. Until the cumulative flow rate reaches a predetermined flow rate, the three-way valve 28 opens the return channel 29b and closes the recovery channel 29a. Once the predetermined flow rate is reached, the three-way valve 28 closes the return channel 29b and opens the recovery channel 29a, thereby switching the outlet direction of the three-way valve 28. In this embodiment, the same control may be performed using the waste channel 29c instead of the return channel 29b. 【0079】 In this embodiment, if the raw material has consistent properties, a sufficiently high-quality concentrated liquid can be obtained even with timer-based switching control. If there are fluctuations in the properties of the supplied raw material, switching control based on the cumulative flow rate of the flow meter is preferable. These switching controls allow for the automatic acquisition of a concentrated liquid with high product quality. 【0080】 Instead of the three-way valve 28 shown in Figures 4 and 5, on-off valves (not shown) may be provided in each of the recovery channel 29a and the return channel 29b (or waste channel 29c). In this case, on-off valves are provided in each of the recovery channel 29a and the return channel 29b (or waste channel 29c), and control can be achieved in the same way as with the three-way valve 28 by switching the on / off valves of the recovery channel 29a and the return channel 29b (or waste channel 29c) ON / OFF. 【0081】 In this embodiment, a flow meter (not shown) may be installed in the heavy liquid discharge pipe. In this case, the flow meter can be used to determine that the concentrated liquid has been recovered when the desired flow rate is reached, and the heavy liquid discharge valve 26 can be controlled to close. 【0082】An example of the operation method of the concentrated liquid recovery apparatus using a centrifugal separator according to this embodiment will be explained with reference to Figure 6. Figure 6 is a diagram showing an example of the operation method of the concentrated liquid recovery apparatus using a centrifugal separator according to this embodiment. Figure 6(A) is the concentrated liquid concentration process, Figure 6(B) is the concentrated liquid recovery process, and Figure 6(C) is the partial discharge process for disposing of any remaining concentrated liquid. First, in the concentrated liquid concentration process shown in Figure 6(A), the raw liquid is introduced from the raw liquid supply pipe 10 and sent to the separation chamber 16, where it is separated into concentrated liquid (heavy liquid) and clarified liquid (light liquid) by centrifugal separation. At this time, since the heavy liquid discharge valve 26 is closed, the concentrated liquid is not discharged and concentration proceeds. Simultaneously, in order to add displacement water to the heavy liquid chamber 21, the on / off valve 25 is opened and displacement water is supplied into the heavy liquid chamber 21 from the upper gap 24A. As a result, the stock solution is continuously introduced during operation, and during the concentration process of the concentrated liquid, the area near the heavy liquid inlet of the heavy liquid impeller 22 is filled with displacement water, thus preventing shearing of the concentrated liquid by the heavy liquid inlet of the heavy liquid impeller 22 during centrifugal separation. Once the concentration process is complete, the process proceeds to the recovery of the concentrated liquid (Figure 6(B)). 【0083】 Next, in the concentrated liquid recovery process shown in Figure 6(B), the heavy liquid discharge valve 26 is opened, the on / off valve 25 is closed, the supply of displacement water is stopped, the concentrated liquid is drawn up from the heavy liquid chamber 21 by the heavy liquid impeller 22, and the concentrated liquid that will become the product is recovered via the heavy liquid discharge pipe 23. 【0084】 Once the recovery of the concentrated liquid is complete, the concentration process (Figure 6(A)) is performed again. These steps are repeated multiple times, for example, twice. By repeatedly performing the concentration and recovery processes, any portion of the concentrated liquid that cannot be discharged during the recovery process accumulates in the centrifuge. In particular, the concentrated liquid accumulates near the corners formed by the rotating body lid 12 and bottom 13 in the separation chamber 16, and any concentrated liquid that cannot be discharged remains there. 【0085】In this embodiment, microorganisms are not discharged by the rotary valve at the bottom 13, but are removed from the heavy liquid chamber 21 side. Therefore, valve discharge by the rotary valve is performed only in cases of maintenance such as cleaning the centrifuge, or in cases of emergency shutdown of the centrifuge, etc. During normal operation, valve discharge of the concentrated liquid using the rotary valve is not performed. 【0086】 To dispose of the concentrated liquid that accumulates in the centrifuge, the partial discharge process shown in Figure 6(C) is intermittently incorporated. At the timing of maintenance such as cleaning the centrifuge, as shown in Figure 6(C), the rotary valve is used to discharge the concentrated liquid that does not become a product for disposal (partial discharge). Since the concentrated liquid discharged in this partial discharge does not become a product, it is preferable to recover it separately from the concentrated liquid that becomes a product recovered from the heavy liquid impeller and, for example, dispose of it. 【0087】 Furthermore, if the concentrated liquid remains in the separation chamber without being discharged, it may solidify and become impossible to discharge. For example, it could cause problems such as the liquid sticking to the separation chamber of the centrifuge and preventing the rotary valve from opening. Additionally, removing the solidified concentrated liquid that cannot be discharged may require extensive maintenance, such as disassembling the centrifuge, which would severely reduce the efficiency of maintenance. 【0088】 Performing this partial discharge makes cleaning the inside of the centrifuge easier. Furthermore, by performing partial discharge intermittently as shown in Figure 6(C), the concentrated liquid can be discharged before it solidifies in the separation chamber, thus preventing problems with the centrifuge. 【0089】 In this embodiment, an example was described in which the steps in Figures 6(A) and 6(B) are repeated twice. However, the number of repetitions is not particularly limited and can be set as appropriate according to maintenance schedules, etc. 【0090】 The following describes embodiments of the present invention, but the present invention is not limited to these embodiments. 【0091】Example 1 A concentration test was performed using the vertical centrifuge shown in Figure 1, with Chlamydomonas culture solution as the stock solution. • Stock solution: Chlamydomonas culture solution SS concentration: 1200 mg / L • Centrifuge: Model "SJ10F Sanitary" 【0092】 The separation plate 14 of the vertical centrifuge 1 separates the Chlamydomonas culture solution (microorganism) into a clear solution and a concentrated solution. The concentrated solution accumulates in the separation chamber 16, and also in the heavy liquid chamber 21. The concentrated solution also accumulates in the channel leading to the heavy liquid chamber 21. 【0093】 Since the culture solution of the microorganism Chlamydomonas is made into a concentrated product, a highly concentrated solution is desired. 【0094】 An experiment was conducted in which the heavy liquid discharge valve 26 was closed to stop the discharge of the concentrated liquid, and the solution was concentrated in batches to obtain a high-concentration Chlamydomonas culture solution as a product. 【0095】 In the experiment, the heavy liquid chamber 21 is filled with concentrated liquid when water replacement is started. The water replacement of the concentrated liquid in the heavy liquid chamber 21 is completed as shown in Figure 2. Tap water was used for water replacement. With the stock solution being supplied from the stock solution supply pipe 10, replacement water is supplied to the heavy liquid chamber 21 from the piping 24. Concentration by batch operation is continued even while water replacement is in progress, and the heavy liquid discharge valve 26 is opened at a time set by the timer to discharge the concentrated liquid and remove it, so that the concentrated liquid does not escape from the clarified liquid side. 【0096】 During the extraction process, the first 200 mL was discarded as it had a low concentration due to water displacement and was not included as the final product concentrate. Product extraction was terminated when the total product volume reached 800 mL. 【0097】 The following measurements were performed on the extracted concentrated microorganisms: a) SS concentration of the concentrated solution = approximately 81.2 g / L b) Concentration ratio = concentrated solution SS / original solution SS = approximately 68 times c) Dissolution rate of the concentrated culture medium = approximately 24.1% Dissolution rate = DS / TSc derived from dissolution (how much of the cells were dissolved) TSc = TS - DS derived from culture medium components DS: Dissolved Solids 【0098】 Example 2 A test was conducted to confirm the feasibility of discharging concentrated algae from the heavy liquid valve using a centrifuge (SJ10F sanitary). There was no leakage from the heavy liquid chamber even when the heavy liquid discharge valve was closed. The back pressure of the heavy liquid when closed was 0.49 MPa, and the increase in current value was slight. When algae came out of the light liquid outlet (clarified liquid outlet), the discharge of algae from the heavy liquid discharge valve was started. Concentrated algae were discharged, and the concentrated liquid was recovered. 【0099】 Comparative Example 1: In Example 2, sampling was performed without supplying displacement water and without closing the heavy liquid discharge valve during discharge. With the heavy liquid discharge valve open, the survival rate of the initial portion discharged was 0%. This is presumed to be due to death by heat generated by the heavy liquid impeller agitation during concentration. 【0100】 1: Vertical centrifugal separator 10: Raw liquid supply pipe 11: Rotating body 12: Rotating body cover 13: Bottom 14: Separation plate 15: Water intake plate 150: Heavy liquid flow path 16: Separation chamber 17: Guide tube 18: Light liquid chamber 19: Light liquid impeller 20: Discharge pipe 21: Heavy liquid chamber 210: Top partition 210a: Front end 211: Side partition 212: Rear partition 22: Heavy liquid impeller 23: Heavy liquid discharge pipe 24: Piping 24A: Upper gap 24B: Displacement water supply section 240B: Inlet 241B: Storage section 242B: Supply flow path 25: On / off valve 26: Heavy liquid discharge valve 27: Pressure gauge 28: Three-way valve 29a: Recovery channel 29b: Return channel 29c: Waste channel 100: Vertical centrifugal separator 103: Rotating body cover 105: Separation plate 106: Water intake plate 112: Adjustment plate 113: Heavy liquid chamber 114: Top partition 114a: Central axis side end 115: Rear partition 116: Heavy liquid impeller 120: Upper gap

Claims

1. A vertical centrifuge for separating a raw liquid containing microorganisms into a heavy liquid and a light liquid by continuously supplying the raw liquid, characterized in that it has a structure for intermittently obtaining a concentrated liquid of microorganisms from the heavy liquid side discharged via a heavy liquid impeller facing the heavy liquid chamber, and has a structure for injecting displacement water into the heavy liquid chamber to replace part or all of the heavy liquid in the heavy liquid chamber.

2. The vertical centrifugal separator according to claim 1, characterized in that the structure capable of injecting the displacement water comprises a displacement water supply unit capable of supplying displacement water to the heavy liquid chamber, a supply channel is formed in the displacement water supply unit, and the supply channel is arranged toward the upper gap of the heavy liquid chamber.

3. The vertical centrifuge according to claim 1, characterized in that the structure for intermittently obtaining a concentrated liquid of microorganisms from the heavy liquid side is configured to intermittently obtain a concentrated liquid of microorganisms from the heavy liquid side by opening and closing a heavy liquid discharge valve provided in a discharge pipe connected to a heavy liquid impeller facing the heavy liquid chamber.

4. The vertical centrifugal separator according to claim 1, characterized in that the heavy liquid chamber is partitioned into a room shape by an upper partition, a side partition, and a rear partition, a heavy liquid impeller for discharging the concentrated liquid in the heavy liquid chamber is disposed on the upper part of the rear partition without an adjustment plate, a heavy liquid channel is formed in the gap between a rotating body lid connected to the side partition and a water intake plate that can send the concentrated liquid in the separation chamber to the heavy liquid chamber, and the water intake plate extends toward the bottom of the separation chamber, with a gap formed between the tip of the water intake plate and the bottom.

5. A method for operating a vertical centrifuge, wherein a stock solution containing microorganisms is continuously supplied to the vertical centrifuge to separate it into heavy liquid and light liquid, and the concentrated microbial solution stored in the heavy liquid side is intermittently removed, characterized in that, before or after the intermittent removal of the concentrated microbial solution from the heavy liquid side, replacement water is injected into the heavy liquid chamber to replace part or all of the heavy liquid with water.

6. The method for operating a vertical centrifuge according to claim 5, characterized in that, when intermittently removing the concentrated microbial solution stored on the heavy liquid side, a heavy liquid discharge valve provided on a heavy liquid discharge pipe connected to a heavy liquid impeller facing the heavy liquid chamber is closed to store the concentrated microbial solution on the heavy liquid side.

7. A concentrated liquid recovery apparatus using a vertical centrifuge according to any one of claims 1 to 4, wherein a heavy liquid discharge pipe is connected to the outlet of the heavy liquid impeller for discharging the concentrated liquid from the heavy liquid chamber via the heavy liquid impeller, a three-way valve is provided in the heavy liquid discharge pipe, and the three-way valve is characterized in that it branches the concentrated liquid discharged from the heavy liquid impeller into a return channel for returning the concentrated liquid to the vertical centrifuge via a stock supply pipe for introducing the stock liquid into the vertical centrifuge, and a recovery channel for recovering the concentrated liquid.

8. A concentrated liquid recovery apparatus using a vertical centrifugal separator according to any one of claims 1 to 4, wherein, when recovering the concentrated liquid discharged from the heavy liquid impeller via a heavy liquid discharge pipe, a three-way valve is provided in the heavy liquid discharge pipe, and the three-way valve is configured to branch into a waste channel for recovering the concentrated liquid discharged from the heavy liquid impeller for disposal and a recovery channel for recovering the concentrated liquid.

9. A concentrated liquid recovery apparatus using a vertical centrifuge according to any one of claims 1 to 4, wherein when the concentrated liquid discharged from the heavy liquid impeller is recovered via a heavy liquid discharge pipe, the heavy liquid discharge pipe is connected to a recovery channel for recovering the concentrated liquid, and a return channel is provided upstream of the recovery channel to return the concentrated liquid to a stock supply pipe for introducing the stock liquid into the vertical centrifuge, and on / off valves are provided in the recovery channel and the return channel, respectively, and the apparatus is configured to allow the concentrated liquid discharged from the heavy liquid impeller to be branched into either the recovery channel or the return channel.

10. A concentrated liquid recovery apparatus using a vertical centrifugal separator according to any one of claims 1 to 4, wherein, when recovering the concentrated liquid discharged from the heavy liquid impeller via a heavy liquid discharge pipe, a recovery channel for recovering the concentrated liquid is connected to the heavy liquid discharge pipe, and a waste channel for recovering the liquid for disposal is provided to branch off upstream of the recovery channel, and on / off valves are provided in the recovery channel and the waste channel, respectively, and the apparatus is configured to allow the concentrated liquid discharged from the heavy liquid impeller to be branched into either the recovery channel or the waste channel.

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