Multi-stage pressure differential generating system

Abstract

To provide a pressure differential generating system capable of generating a pressure differential within a plurality of vessels from 1 CH.SOLUTION: Two adjacent closed vessels 23, 23 are flow-line connected via a differential pressure valve 39, and for instance, the closed vessels 23A, 23B, 23C, and 23D are connected in a rosary-like fashion to form a series connection. Then, the closed vessel 23A is connected to a pressure controller 3; and the differential pressure valves 39A, 39B, and 39C are set up with a pressure controller 3 side facing a high-pressure upstream side, so that the differential pressure difference between them is differential pressure valve 39A≥differential pressure valve 39B≥differential pressure valve 39C. Also, the control pressure of the closed vessel 23A is set to a target value higher than the differential pressure valve 39A. Since the pressure inside the subsequent closed vessels 23B, 23C, etc. is linked to a differential pressure difference based on the control pressure of the closed vessel 23A, the pressure inside the closed vessel 23A in the uppermost stage is set to a fixed constant value, and it is possible to stabilize the pressure inside the subsequent closed vessels 23B, 23C, etc. As a consequence, various pressure patterns can be formed by changing the control pressure of the closed vessel 23A and the differential pressure difference of the differential pressure valve 39.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a multi-stage pressure difference generating system that can generate a pressure difference inside multiple sealed containers with one channel control. [Background technology]

[0002] In recent years, research into creating organs outside of the body has become increasingly active, and various perfusion culture systems have been developed as experimental tools to support this research. However, in order to promote the inflow of perfusion fluid into biological specimens, it has recently been proposed to apply pressure to the biological specimens from the outside, as described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-126051 Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the type of biological sample, the culture environment, and even the purpose of the test, it may be necessary to vary the pressure conditions in multiple containers. In addition, a preliminary test may be performed to determine the optimum pressure before the actual test, but it is preferable to perform the preliminary test only once. If the pressure control device used for such testing is one that controls the pressure inside the vessel using the one vessel, one channel method, the advantages of one vessel, one channel, such as fast pressure response and high pressure control accuracy, are ensured, but channel control is required for each vessel, which makes the structure more complex and expensive. On the other hand, it is possible to configure the pressure inside multiple containers using a multiple container 1 channel system, where the pressure inside multiple containers is controlled simultaneously from 1 channel via a pressure buffer, but the presence of the buffer not only slows down the pressure response, but also increases the possibility of pressure differences between the containers due to flow path resistance.Furthermore, it is not possible to distribute pressure conditions across multiple containers in the first place.

[0005] The present invention has been made in response to the above-mentioned conventional problems, and its object is to provide a new and useful multi-stage pressure difference generation system that can generate a pressure difference in multiple containers from one channel. [Means for solving the problem]

[0006] The present invention has been made to solve the above-mentioned problems, and is a multi-stage pressure difference generating system comprising a plurality of sealed containers connected in series via non-powered differential pressure valves whose inlets are oriented in one direction, and a pressure control device having a pump unit connected to the uppermost sealed container, wherein the pressure differences between adjacent differential pressure valves are set to be larger on the upstream side or the same, and the control pressure of the pressure control device is set to a target value such that the internal pressure of the uppermost sealed container is larger than the differential pressure difference of the differential pressure valve on the most upstream side, thereby generating a pressure difference that changes proportionally to the internal pressure of each of the plurality of sealed containers.

[0007] Preferably, the pressure difference of the differential pressure valve is changeable, and by changing the pressure difference, the pressure difference pattern of the pressures inside each of the plurality of containers can be set to any desired pattern. Preferably, the pump unit is a reversible peristaltic pump. Preferably, the differential pressure valve is a direct acting relief valve.

[0008] Preferably, the sealed container unit is made up of a sealed container and a pair of tubes inserted into the sealed container to communicate with the interior thereof. Preferably, a plurality of sealed containers are integrally attached to a single base plate. [Effects of the Invention]

[0009] According to the multi-stage pressure difference generating system of the present invention, pressure differences can be generated in multiple containers from one CH. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall configuration diagram of a multi-stage pressure differential generating system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a configuration diagram of a pressure control device of the multi-stage pressure difference generating system of FIG. [Figure 3] 2 is a perspective view showing a state in which a sealed container is set in an adapter in the multi-stage pressure difference generating system of FIG. 1. FIG. [Figure 4] FIG. 4 is a perspective view of the state where the cover is removed from FIG. 3. [Figure 5] FIG. 2 is a perspective view of a differential pressure valve of the multi-stage differential pressure generating system of FIG. 1. [Figure 6] FIG. 6 is an exploded perspective view of the differential pressure valve of FIG. 5. [Figure 7] FIG. 6 is a vertical cross-sectional view of the differential pressure valve of FIG. 5. [Figure 8] 2 is a graph confirming the proportional change in pressure between vessels in the multi-stage pressure differential generating system of FIG. 1. [Figure 9] FIG. 9 is an image diagram of the differential pressure chain between the containers in FIG. 8. [Figure 10] 2 is a graph confirming proportional changes in pressure among multiple vessels in the multi-stage pressure differential generating system of FIG. 1; [Figure 11] FIG. 11 is an image diagram of the differential pressure chain between the containers in FIG. [Figure 12] 10 is an example of pressure condition distribution among multiple containers. DETAILED DESCRIPTION OF THE INVENTION

[0011] A multi-stage pressure difference generating system 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the multi-stage pressure difference generating system 1 is configured by connecting a pressure control device 3 and sealed containers 23, 23, . . . with tubes.

[0012] A peristaltic pump (pump unit) 7 is provided on the top surface of the housing 5 of the pressure control device 3. This peristaltic pump 7 is capable of rotating forward and reverse. One tube connection of the peristaltic pump 7 is open to the atmosphere, and a flexible silicone tube 9 is connected in communication with the other tube connection. The tube 9 branches midway, and branch tube 11 enters the interior of the housing 5 where it is sealed to a pressure sensor 13. Pressure sensor 13 is a gauge pressure type, and the pressure received by its pressure-sensitive surface is sent to controller 15 as an analog control signal. Controller 15 receives this analog control signal as a measured value (sensor data) of the pressure inside connected sealed container 23, and performs calculations using an internal MCU to match the value to a target value, creating and sending out an analog control signal. This signal is sent to regulator 17, where it is converted into a pulse voltage signal, and finally sent to the pump drive board of peristaltic pump 7. The pump drive board drives the pump by eccentrically moving the pressurizing member of peristaltic pump 7 at a rotation speed corresponding to the frequency of the pulse voltage signal. The pump drive board is located inside housing 5.

[0013] Therefore, by combining forward (discharge) operation and reverse (suction) operation caused by forward and reverse rotation of the peristaltic pump 7, it is possible to finely adjust the pressure inside the connected sealed container 23 (described below) to match the target value with high precision. The other end of tube 9, spanning branch tube 11, is connected to filter 19, passed through another similar tube 21, and then connected to sealed container 23. As will be described later, this tube 21 is also used with different lengths to connect containers, and in that sense it does not represent a single tube.

[0014] As shown in Figures 3 and 4, the sealed container 23 is composed of a container 25 and a lid 27. The container 25 is a commercially available shallow dish made of polystyrene and is open at the top. The lid 27 is made of polycarbonate and is rigid. A circular silicone rubber packing is fitted to the underside of the lid 27, corresponding to the circular upper edge of the container 25. When the lid 27 is placed on the upper edge of the container 25 with the rubber packing pressed against it, the sealed container 23 is formed.

[0015] Reference numeral 29 denotes an adapter, and a base plate 31 of this adapter 29 is provided with recesses into which two containers 25, 25 can be fitted and set. Near the set container 25, two flat head screws 33, 33 are inserted from below and stand upright, and nuts 35, 35 with knurled screws are screwed onto the respective screw shafts. On the outer edge of the lid portion 27, concavely protruding engagement portions 27a, 27a are provided in a point-symmetrical positional relationship in the circumferential direction, and by engaging the screw shaft of a flat head screw 33 with each engagement portion 27a and tightening it with a nut 35, the above-mentioned sealed container 23 is formed and maintained in that state. By using this adapter 29, two airtight containers 23, 23 can be set at the same time.

[0016] Two through holes are formed in the lid 27, which communicate with the inside of the container, and one end of SUS pipes 37, 37 is airtightly inserted into these through holes to form a unit. One end of the tube 21 is fitted onto the outside of the pipe 37 and connected to communicate with it. The other end of the tube 21 is connected to a differential pressure valve 39 . As shown in the perspective view of Fig. 5 and the exploded perspective view of Fig. 6, connecting portions 43, 43 are screwed onto both axial sides of a cylindrical case 41 of the differential pressure valve 39. An insertion hole is formed in the axial center of this connecting portion 43, and a SUS pipe 45 is inserted airtightly through it.

[0017] The differential pressure valve 39 is a non-powered, direct-acting relief valve that opens when the pressure on the inlet side exceeds the pressure on the outlet side by a specified value, allowing air to flow only from the inlet to the outlet. As shown in Figure 7, a movable shaft 47 is housed inside the case 41 so that it can slide axially. A round wire spring 51 is compressed between a retaining block 49 located on the relatively low-pressure outlet side and the spring locking portion of the movable shaft 47, biasing the movable shaft 47 in the valve closing direction (downward). An O-ring 53 is attached to the flange-shaped valve portion of the movable shaft 47. A C-shaped retaining ring 55 is fitted on the outlet side to prevent it from coming loose. The main body side of the case 41 etc. is made of POM, the round wire spring 51 is made of SUS304, and the O-ring 53 is made of NBR.

[0018] With this configuration, the bottom is the inlet (high pressure) and the top is the outlet (low pressure). When the pressure difference exceeds a specified value, the force exceeds the biasing force of the wire spring 51 and pushes up the operating shaft 47, creating a gap between the O-ring 53 and the case 41. Air flows through this gap, shifting the pressure from the high-pressure side to the low-pressure side. In other words, the <differential pressure valve open> mode is activated. On the other hand, when the pressure difference falls below a specified value, the biasing force of the wire spring 51 becomes dominant, causing the O-ring 53 to tightly contact the case 41, preventing pressure from leaking. In other words, the <differential pressure valve closed> mode is activated.

[0019] The differential pressure valve 39 is compact and has good pressure response. In addition, since it is applicable over a wide range of pressures and temperatures, it is a component with necessary and sufficient performance for using the multi-stage pressure difference generating system 1 to pressurize a culture device.

[0020] In FIG. 1, (sealed container 23 - tube 21 - differential pressure valve 39 - tube 21 - sealed container 23), two adjacent sealed containers 23, 23 are connected via a differential pressure valve 39, and overall, four sealed containers 23A, 23B, 23C, 23D are connected in series like a daisy chain. The tube 21 that is out of the row of the first-tier sealed container 23A at the top is connected to the pressure control device 3, and the tube 21 that is out of the row of the fourth-tier sealed container 23D at the bottom is sealed with a cap 57.

[0021] Differential pressure valves 39A, 39B, and 39C are interposed between the sealed containers 23 in the following order, sealed container 23A → differential pressure valve 39A → sealed container 23B → differential pressure valve 39B → sealed container 23C → differential pressure valve 39C → sealed container 23D, with the pressure control device 3 side aligned on the high-pressure upstream side so that air only flows in the direction from the top sealed container 23A to the last sealed container 23, and the differential pressure differences are set so that differential pressure valve 39A ≧ differential pressure valve 39B ≧ differential pressure valve 39C. In addition, the internal pressure (control pressure) of sealed container 23A is set to a target value higher than that of differential pressure valve 39A.

[0022] In the multi-stage pressure difference generating system 1 configured as described above, the pressure between the containers changes proportionally. Figure 8 is a graph showing the test results. Note that in this test, the number of sealed containers 23 was reduced, and the second-stage sealed container 23B was the last stage, not the fourth stage. The pressure inside the sealed container 23A is at a control pressure value controlled by the pressure control device 3, and the pressure inside the sealed container 23B is at a pressure value obtained by subtracting the pressure difference of the differential pressure valve 39A from the control pressure value. As shown in this confirmation graph, it has been confirmed that the pressure inside the second-stage container changes proportionally to the pressure inside the first-stage container.

[0023] 9, if the pressure inside the sealed container 23A (control pressure) is set to 300 mmHg and the differential pressure difference of the differential pressure valve 39A is set to 100 mmHg, the inside of the sealed container 23A will be pressurized and saturated at the control pressure (300 mmHg), and the differential pressure valve 39A will open, and the air flow will cause pressure to move into the second-stage pressure vessel 23B, and when the differential pressure difference falls below the threshold (= specified value), the differential pressure valve 39A will close and no further pressure will move. As a result, the pressure inside the second-stage sealed container 23B will reach a pressure (= 200 mmHg) obtained by subtracting the differential pressure difference (= 100 mmHg) from the control pressure (= 300 mmHg), and will be maintained at that pressure.

[0024] FIG. 10 is a confirmation graph of the test results when the sealed containers 23 are connected in series in four stages. The internal pressure of sealed container 23A is at a controlled pressure value controlled by pressure control device 3. As shown in this confirmation graph, it has been confirmed that the internal pressure of sealed container 23B changes proportionally to the internal pressure of sealed container 23A, the internal pressure of sealed container 23C changes proportionally to the internal pressure of sealed container 23B, and the internal pressure of sealed container 23D changes proportionally to the internal pressure of sealed container 23C.

[0025] Furthermore, as shown in the image diagram of Figure 11, if the third-stage sealed container 23C is set as the last stage instead of the fourth stage, and the internal pressure (control pressure) of sealed container 23A is set to 300 mmHg, and the differential pressure differences between differential pressure valves 39A and 39B are both set to 100 mmHg, the inside of sealed container 23A will be pressurized at the control pressure (300 mmHg) and saturated, and differential pressure valve 39A will open, and pressure will move into second-stage sealed container 23B due to the air flow.Furthermore, the internal pressure of sealed container 23B will increase, and when the differential pressure difference between differential pressure valve 39B exceeds the threshold (= specified value), differential pressure valve 39B will open and pressure will move from sealed container 23B into sealed container 23C.

[0026] When the pressure difference between differential pressure valve 39B falls below a threshold (specified value), differential pressure valve 39B closes, and when the pressure difference between differential pressure valve 39A falls below a threshold (specified value), differential pressure valve 39A closes and no pressure transfer occurs. As a result, the pressure in second-stage sealed container 23B reaches and is maintained at a pressure (=200 mmHg) obtained by subtracting the pressure difference between differential pressure valve 39A (=100 mmHg) from the control pressure (=300 mmHg), and the pressure in third-stage sealed container 23C reaches and is maintained at a pressure (=100 mmHg) obtained by subtracting the pressure difference between differential pressure valve 39A (=100 mmHg) and differential pressure valve 39B (=100 mmHg) from the control pressure (=300 mmHg).

[0027] In this way, in the multi-stage pressure difference generating system 1, the internal pressure (control pressure) of the uppermost sealed container 23A is used as a reference, and the internal pressures of the subsequent sealed containers 23B, 23C, ... are linked to the differential pressure difference. Then, by combining the pressure control device 3, which can control pressure with high precision, with the differential pressure valve 39, which has good pressure responsiveness, it is possible to fix the internal pressure of the uppermost sealed container 23A and stabilize the internal pressures of the subsequent sealed containers 23B, 23C, ...

[0028] Differential pressure valves 39 are available in multiple types according to the pressure difference (7.5 mmHg, 30 mmHg, 50 mmHg, 75 mmHg, 100 mmHg, 150 mmHg, 300 mmHg, 525 mmHg), and as shown in Figure 12, by changing the combination of the pressure inside the first-stage sealed container 23A (control pressure) and the differential valve 39, pressure differences with various pressure gradations can be generated. That is, pressure differences can be generated in a desired pattern within a plurality of sealed containers 23 from one CH.

[0029] Although the embodiments of the present invention have been described in detail above, the specific configuration is not limited to these embodiments, and the invention also includes design changes within the scope of the present invention without departing from the gist of the present invention. For example, there are weight-type and pilot-type differential pressure valves, but the former have the disadvantages of being heavy and limiting the installation direction, while the latter can adjust pressure over a wide range and can set pressure even in low pressure ranges, but have the disadvantage of being large and expensive. Considering these, the direct-acting type adopted in the embodiment of the present invention is the most recommended at present, but is not limited from a technical standpoint. [Explanation of symbols]

[0030] 1...Multi-stage pressure difference generation system 3...Pressure control device 5...Housing 7...Peristaltic pump 9...Tube 11...Branch tube 13...Pressure sensor 15...Controller 17...Regulator 19...Filter 21...Tube 23...Sealed container 25...Container 27...Lid part 27a...Engagement part 29...Adapter 31...Base plate 33...Flat head screw 35...Nut 37...Pipe 39...Differential pressure valve 41...Case 43...Connection part 45...Pipe 47...Moving shaft 49...Pressing block 51...Round wire spring 53...O-ring 55...C-type retaining ring 57...Cap

Claims

1. The pressure control device includes a plurality of sealed containers connected in series via non-powered differential pressure valves whose inlets are oriented in one direction, and a pump unit connected to the topmost sealed container, A multi-stage pressure difference generating system characterized in that the pressure differences between adjacent differential pressure valves are set to be larger or the same on the upstream side, and the control pressure of the pressure control device is set to a target value such that the internal pressure of the uppermost sealed container is larger than the differential pressure difference of the differential pressure valve on the most upstream side, thereby generating a pressure difference that changes proportionally to the internal pressure of each of the multiple sealed containers.

2. 2. The multi-stage pressure differential generating system according to claim 1, A multi-stage pressure difference generation system characterized in that the pressure difference of the differential pressure valve is changeable, and by changing the pressure difference, the pressure difference pattern within each of the multiple containers can be set to any desired one.

3. 3. The multi-stage pressure differential generating system according to claim 2, A multi-stage pressure difference generating system, characterized in that the pump unit is composed of a peristaltic pump that can rotate forward and backward.

4. 4. The multi-stage pressure differential generating system according to claim 3, A multi-stage pressure difference generating system, wherein the differential pressure valve is composed of a direct acting relief valve.

5. 5. The multi-stage pressure differential generating system according to claim 4, A multi-stage pressure differential generating system, characterized in that a sealed container unit is composed of a sealed container and a pair of tubes inserted into the sealed container to communicate with the interior thereof.

6. 6. The multi-stage pressure differential generating system according to claim 5, A multi-stage pressure differential generating system characterized in that a plurality of sealed containers are attached to a single base plate and integrated together.

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