Integrity test device and integrity test device system

Abstract

To allow an accurate and rapid increase of pressure in a sample tank in which a sample is arranged, by a simple configuration.SOLUTION: An integrity test device includes: a main tube path defined between an input port connected to a fluid source tube path leading to a fluid source and an output port connected to a tube path leading to a sample tank storing a sample; an electromagnetic valve arranged in the main tube path, for controlling the flow of the main tube path; a pressure meter for measuring the pressure of the main tube path; and a control unit for controlling the opening and closing, and adds a test target pressure Pspec to the sample. The control unit executes a preparation process and a real test process.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an integrity tester and an integrity tester system. [Background technology]

[0002] Conventionally, for products such as membrane filters made of membrane films, an integrity test is performed before or after the actual filtration process to non-destructively check whether the product has the expected performance (filtration accuracy) by placing a product sample in a sample tank and pressurizing the sample tank.

[0003] An integrity tester system for carrying out a product integrity test generally comprises a sample tank in which a product sample is placed and isolated from the external environment, a fluid source for a fluid used for pressurization for the integrity test, and an integrity tester. Generally, a gas (gas fluid) such as air or nitrogen is used as the pressurized fluid. The integrity tester is a device for introducing a fluid from a fluid source into the sample tank while controlling the pressure and flow rate, and is a device that performs a pressure control function of controlling the pressure of the sample tank by adjusting the pressure or flow rate of the fluid in the integrity tester system.

[0004] The integrity tester is generally configured as a unitary, portable, detachable integrity tester that can be connected to and disconnected from a sample tank and a fluid source of the integrity tester system.

[0005] Integrity testing is performed by first placing a sample in a sample tank after performing necessary pretreatment in an integrity testing device system. For example, if the sample is a membrane filter, the membrane filter is completely wetted with liquid as pretreatment and placed in the sample tank in that state. After placing the sample in the sample tank, a pressurized fluid is flowed from a fluid source into the tank to increase the pressure inside the sample tank to a predetermined pressure, and then the flow of fluid from the fluid source is blocked to maintain that pressure for a predetermined time, and the amount of pressure drop thereafter is observed to evaluate the performance of the sample. For example, if the sample is a membrane film, a test fluid (gas) is flowed on any surface of the membrane filter to generate a predetermined pressure difference between the front and back of the sample, and the pressure is maintained for a predetermined time, and the amount of pressure drop thereafter is observed to evaluate the performance of the sample.

[0006] As a method for increasing pressure to a predetermined test pressure using an integrity test device, there is a method for adjusting the average flow rate by opening and closing a solenoid valve, or a method for finely adjusting the flow rate of the fluid by adjusting the valve opening degree using a regulator. For example, Patent Document 1 discloses an integrity test device that increases pressure while adjusting the flow rate with a solenoid valve.

[0007] Furthermore, in the flow rate adjustment in the integrity tester of Patent Document 1, an integrity tester is disclosed that opens and closes a solenoid valve by controlling an integral element in addition to a proportional element. In the flow rate adjustment of the integrity tester disclosed in Patent Document 1, the pressure is initially increased to approximately a specified pressure by controlling the proportional element with a large flow rate mass flow controller, and then the pressure is finely increased to the specified pressure by controlling the integral element with a small flow rate mass flow controller.

[0008] However, the integrity test equipment that controls the flow rate using two controllers and proportional element control has a problem that the control system becomes large and it is difficult to realize a compact integrity test equipment. A compact integrity test equipment with a simple structure is required. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 2945988 specification Summary of the Invention [Problem to be solved by the invention]

[0010] In the portable integrity tester, the pressure source of the pressurized fluid and the sample are connected to the entire flow circuit including the tank in which the sample is placed, and the internal flow circuit of the portable integrity tester is designed separately from the liquid flow circuit. Therefore, in the case of the portable integrity tester, the pressure detection value of the pressure gauge placed in the tank in which the sample is placed is generally different from the pressure detection value of the internal pressure of the integrity tester.

[0011] For example, when the flow circuit of the integrity tester is enlarged in order to increase the flow rate during pressurization, a pressure rise and drop occurs unsteadily before and after the flow of pressurized fluid from the fluid source is cut off. The integrity test cannot be started until this unsteady pressure fluctuation subsides.

[0012] Integrity testing requires accurate pressure buildup in the sample tank. For example, if the sample is extremely thin, such as a membrane film, excessive pressure buildup can damage the sample. On the other hand, integrity testing cannot be completed if the pressure cannot be raised to the required level. In addition, to complete testing of many samples in a short period of time, it is necessary to efficiently build up and maintain the pressure to the required level for each sample test.

[0013] For example, if the test pressure is higher than the specified pressure, the pressure drop will be large and accurate measurement will not be possible. If the difference between the test pressure and the specified pressure is too large, the liquid film on the membrane will be partially reduced (from large pores), leaving some parts unwet, resulting in a large pressure drop.

[0014] For example, if the sample tank is large, it takes time to increase the pressure, which increases the downtime of the system. Furthermore, when performing integrity tests on many samples, it is necessary to perform the integrity test on each sample in a short time in order to shorten the overall test time.

[0015] Therefore, it is necessary to accurately increase the pressure in the sample tank in which the sample is placed within a short period of time. [Means for solving the problem]

[0016] The present invention is provided with a main pipe defined between an input port connected to a fluid source pipe leading to a fluid source and an output port connected to a pipe leading to a sample tank containing a sample, a solenoid valve disposed in the main pipe for controlling the opening and closing of the flow of the main pipe, a pressure gauge for measuring the pressure of the main pipe, and a controller for controlling the opening and closing of the main pipe, and a test target pressure P spec and a controller for implementing the integrity test apparatus, the controller implementing the integrity test apparatus performing a preparation process and an actual test process.

[0017] An integrity tester system comprising a fluid source, a fluid source line leading to the fluid source, a sample tank containing a sample, a line leading to the sample tank, and an integrity tester, the integrity tester comprising a main line defined between an input port connected to the fluid source line and an output port connected to the line leading to the sample tank, a solenoid valve disposed in the main line and controlling the opening and closing of the flow in the main line, a pressure gauge measuring the pressure in the main line, and a controller for controlling the opening and closing, and a test target pressure P spec The controller is implemented by an integrity tester system that performs a preparation process and an actual test process. Effect of the Invention

[0018] The integrity test device of the present invention has a simple structure and enables accurate and rapid pressure increase within a sample tank in which a sample is placed. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic configuration diagram of an integrity test device system and an integrity test device according to an embodiment of the present invention; [Figure 2A] 4 is a conceptual diagram of a pressure control algorithm performed by the integrity test device according to the embodiment of the present invention. FIG. [Figure 2B] 4 is a conceptual diagram of an algorithm of an actual test process among the pressure control algorithms performed by the integrity test device according to the embodiment of the present invention. FIG. [Diagram 3] 4 is a conceptual diagram of pressure change in pressure control performed by a controller of the integrity test device according to the embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] [Example] (Configuration of the integrity test device 1 and the integrity test device system 10) The configurations of an integrity tester 1 and an integrity tester system 10 will be described with reference to Fig. 1. Fig. 1 is a schematic diagram of the integrity tester system and integrity tester according to an embodiment of the present invention.

[0021] The integrity tester system 10 includes an integrity tester 1, a fluid source 11 in which a gaseous fluid serving as a test fluid is stored, a fluid source line 111 which is a line for the fluid from the fluid source 11, a sample tank 12 in which a sample S such as a membrane filter which is the subject of the integrity test is stored, and a sample tank line 121 which is a line for the fluid to the sample tank 12. In this specification, as a representative example, the sample S will be described as a thin film having a front and back such as a membrane filter. A tank line pressure gauge 13 which detects the internal pressure of the sample tank 12 is disposed in the sample tank line 121.

[0022] The integrity test device 1 is a device for performing a pressure hold test among other integrity tests. A sample S is placed in a sample tank 12 as a sample.

[0023] The integrity test device 1 includes a main line 2, a solenoid valve 3, a pressure gauge 4, and a controller 5. The main line 2 is a line having an upstream input port 2a and a downstream output port 2b at both ends, and defines a flow from upstream to downstream. A solenoid valve 3 is disposed in the main line 2. The main line 2 is composed of an upstream line 21 between the solenoid valve 3 and the input port 2a, and a downstream line 22 between the solenoid valve 3 and the output port 2b.

[0024] A pressure gauge 4 is disposed in the main pipeline 2. The pressure gauge 4 detects the pressure in the main pipeline 2. In particular, the pressure gauge 4 is disposed in the downstream pipeline 22, which is the pipeline on the sample tank 12 side, so that the pressure in the sample tank 12 can be detected accurately at all times. The pressure gauge 4 and the controller 5 are electrically connected, and the pressure in the main pipeline detected by the pressure gauge 4 is input to the controller 5.

[0025] The solenoid valve 3 and the controller 5 are electrically connected, and the controller 5 controls the opening and closing (opening and closing) of the solenoid valve 3. When the solenoid valve 3 is in a closed state, the flow between the upstream pipe 21 and the downstream pipe 22 is interrupted and the flow in the main pipe 2 stops, and when the solenoid valve 3 is in an open state, the flow between the upstream pipe 21 and the downstream pipe 22 is free and a flow is generated in the main pipe 2.

[0026] The input port 2a of the integrity tester 1 is structured so that a fluid source line 111 can be detachably connected thereto, and the output port 2b of the integrity tester 1 is structured so that a sample tank line 121 can be detachably connected thereto. When the input port 2a and the fluid source line 111 are separated and the output port 2b and the sample tank line 121 are separated, the integrity tester 1 can be defined as a portable unit independent of the integrity tester system 10.

[0027] When the input port 2a is connected to the fluid source line 111 and the output port 2b is made connectable to the sample tank line 121, a flow circuit of a gas fluid is formed in the integrity tester system 10 from the fluid source 11 through the fluid source line 111, the upstream line 21, the downstream line 22, and the sample tank line 121 to the sample tank 12. Hereinafter, this state is referred to as the installed state of the integrity tester 1. Also, the flow circuit from the fluid source 11 to the inside of the sample tank 12 is referred to as the integrity test flow circuit.

[0028] Valves other than the solenoid valve 3 can be disposed in the fluid source conduit 111 and the sample tank conduit 121 as necessary. In the sample tank 12, a gas fluid is introduced into the sample tank 12 from the tank inlet port 12a, and a flow R1 is formed which passes from the outside of the sample S to the front and back of the sample S as a diffusion flow and is discharged from the inside of the sample S to the outside of the sample tank 12 via the tank discharge conduit 122. A discharge pipe valve 122a is disposed in the tank discharge conduit 122.

[0029] Closing the solenoid valve 3 blocks the flow from the fluid source 11 to the sample tank 12, but the sample S can be held in the sample tank 12 with a pressure difference occurring between the front and back of the sample. In the integrity test (pressure hold test), the change in this pressure difference over time when the solenoid valve 3 is closed is observed. When the downstream of the discharge pipe valve 122a is opened to the atmosphere, the change in pressure indicated by the pressure gauge 4 over time is observed. In the integrity test (pressure hold test), the discharge pipe valve 122a is opened to leave the tank discharge pipe 122 open, and the inlet pipe 123 is closed.

[0030] In the integrity test (pressure hold test), pressurized fluid is applied from the primary side of the filter cartridge, causing the pressurized fluid to dissolve in the liquid film in the pores of the membrane (primary side), and the dissolved pressurized fluid diffuses from the back side of the membrane (secondary side) and is discharged (in small amounts) from the tank discharge pipe 122.

[0031] In the integrity test (diffusion flow), the pressurized fluid discharged (in minute amounts) from the tank discharge line 122 is measured by a flow meter on the secondary side. The integrity test device of the present invention is used for an integrity test (pressure hold test) in which the flow rate is indirectly measured by the pressure change on the primary side of the pressurized fluid.

[0032] Since the pressure gauge 4 is disposed upstream of the tank pipe pressure gauge 13, a difference occurs between the pressure detection value of the pressure gauge 4 and the pressure detection value of the tank pipe pressure gauge 13, such that the pressure detection value of the pressure gauge 4 is higher than the pressure detection value of the tank pipe pressure gauge 13 due to pressure loss caused by fluid resistance in the pipe. In addition, when the solenoid valve 3 is open and a flow is occurring in the main pipe 2, a difference occurs transiently between the pressure detection value of the pressure gauge 4 and the pressure detection value of the tank pipe pressure gauge 13 due to the difference in dynamic pressure components caused by the flow.

[0033] An inlet pipe 123 extending from a fluid (liquid) source (not shown) is disposed in the sample tank 12. When the plant is in operation, liquid is introduced into the sample tank 12 from the inlet pipe 123, passes from the outside of the sample S through the front and back of the sample S, and is discharged from the inside of the sample S to the outside of the sample tank 12 via the tank discharge pipe 122, forming a liquid flow R2.

[0034] In the test using flow R2, the membrane is in a state where it has acquired complete wettability and has lost its breathability (permeability of gas and fluid). The integrity test targeted by the integrity test device 1 of the present invention does not target the test using flow R2.

[0035] (Integrity Test Boosting Algorithm) The controller 5 executes an integrity test boosting algorithm in a state where the integrity test device 1 is attached and assembled in the integrity test device system 10. FIG. 2A shows the integrity test boosting algorithm. The integrity test boosting algorithm includes a preparation process S1 and an actual test process S2. FIG. 2B shows the algorithm of the actual test process S2. The preparation process S1 is a process for determining in advance conditions for executing the actual test process S2 in order to execute the actual test process S2 for any membrane film. The actual test process S2 is the test start pressure P init Test target pressure P spec The pressure is increased to the test target pressure P spec It is a process for loading up to

[0036] Furthermore, in the present invention, as the actual test process S2 of the integrity test device 1, the test target pressure P spec Instead of increasing the pressure to the test start pressure P init Test target pressure P spec The voltage is boosted up to N times in total. The last boost out of the total boost count N is defined as a slight boost process, and the previous (N-1) boosts are defined as a coarse boost process. The rough boost process and the slight boost process respectively mean a process of boosting the voltage by a large boost amount and a process of boosting the voltage by a small boost amount. The rough boost process and the slight boost process will be described in detail in the actual test process S2. The slight boost process is defined as the last boost out of the total boost count N divided further into M times of slight boosts.

[0037] (Preparation process S1) The preparation process S1 will be described with reference to Figures 2A, 2B and 3. Figure 2A is a diagram conceptually showing the flow of a boost algorithm executed by the integrity test device 1. Figure 2B is a diagram conceptually showing the flow of an algorithm of an actual test process among the boost algorithms executed by the integrity test device 1. Figure 3 is a conceptual diagram of pressure change in boost control performed by a controller of the integrity test device according to the embodiment of the present invention.

[0038] (Preparation process S1) The preparation process S1 starts with the integrity test device 1 installed. The preparation process S1 includes pressure rise rate measurement, delay time measurement, and actual test parameter determination. The pressure rise rate measurement is performed by measuring the pressure rise rate V p is measured based on the pressure detected by the pressure gauge 4.

[0039] The pressure in the main line 2 when the internal pressure of the fluid source 11 is directly loaded on the main line 2 is defined as an initial pressure P0. In reality, the initial pressure P0 is the pressure value detected by the pressure gauge 4 before the solenoid valve 3 is opened. The pressure gauge 4 constantly detects the pressure in the main line 2. The pressure in the main line 2 detected by the pressure gauge 4 is sent to the controller 5.

[0040] First, the controller 5 opens the solenoid valve 3 and waits a predetermined preparatory pressure rise time t m After the elapse of the predetermined preparatory pressure rise time t, the solenoid valve 3 is closed. As a result, the entire integrity test flow circuit is filled with gas fluid, and the internal pressure of the fluid source 11 is directly applied to the main line 2. m The pressure in the main line 2 after the time has elapsed and the pressure has become steady is called steady pressure P test Then, the pressure rise rate V is calculated from the following formula (1). p Request. V p =(P test -P0) / t m (1)

[0041] In addition, the boost speed V p The appropriate range of the value of V and a predetermined critical value (upper limit of the allowable pressure rise rate) are determined in advance. p When the critical value is exceeded, it means that the flow rate of the gas fluid in the main line 2 is too large relative to the volume of the sample tank 12, or the volume of the sample tank 12 is too small. After the solenoid valve 3 is opened by the controller 5, the pressure in the main line 2 is constantly detected by the pressure gauge 4, and the pressure rise time t mThe steady pressure P is the pressure in the main line 2 after test Detect the predetermined preparatory voltage rise time t m Before the time has elapsed, the boost rate V p If the pressure rise rate exceeds a predetermined critical value (the upper limit of the allowable pressure rise rate), the pressure rise is stopped.

[0042] Predetermined preparation boost time t m Before the time has elapsed, the boost rate V p When the boost rate V exceeds a predetermined critical value (upper limit of the allowable boost rate), the integrity test device 1 notifies the user of the boost rate V by any notification means such as a display (not shown) or a voice. p When this notification is given, the user of the integrity test device 1 adds an appropriate orifice to the fluid source line 111 and the sample tank line 121, or changes the already installed orifice to an appropriate one. p By checking that the pressure exceeds a predetermined critical value, it is possible to prevent the sample tank from exceeding the test target pressure before the start of the actual test process S2.

[0043] On the other hand, the time it takes for the pressure fluctuation of the pressure detected by the pressure gauge 4 to settle after the solenoid valve 3 is closed is defined as the delay time. The delay time is measured when the pressure detected by the pressure gauge 4 reaches a steady pressure P test Transient delay time t d The delay time is measured by opening the solenoid valve 3 by the controller 5 and then closing the solenoid valve 3 by the controller 5. It may also be measured when the solenoid valve 3 is closed for pressure rise speed measurement. That is, first, the solenoid valve 3 is opened once by the controller 5 and then closed. Immediately after this closure, the pressure detected by the pressure gauge 4 and the pressure detected by the tank line pressure gauge 13 exhibit different pressure fluctuation behaviors, but when a predetermined time has passed after the solenoid valve 3 is closed and a steady state is reached, the steady pressure P testThe pressure fluctuations of the pressure detected by the tank line pressure gauge 13 and the pressure detected by the tank line pressure gauge 13 decrease and settle to a stable value. The time it takes for the pressure fluctuations to decrease and settle to a stable value is called the delay time t d The delay time t d can be defined as the time when the pressure fluctuations settle within a given tolerance.

[0044] The actual test parameters are determined by the pressure rise rate V p Measurement results and delay time t d The measurement results and the test target pressure P spec The actual test parameters are determined based on the total number of boosts N in the actual test, the number of minute boosts M, and the test target pressure P spec To determine:

[0045] Test target pressure P spec is defined as the pressure difference to be applied between the front and back of the material of the specimen S in the integrity test (pressure hold test). The test target pressure P spec can also be a parameter value that can be arbitrarily set by the user through an input device (not shown) in the integrity test device 1.

[0046] Test target pressure P spec is the target pressure at the pressure gauge 4 when the controller 5 in the integrity test device 1 increases the pressure based on the pressure gauge 4, and is the test specification pressure required in the integrity test. At this time, the test target pressure P spec is a value including tolerance, and can be set arbitrarily according to the contents of the test. Also, if the pressure detected by the pressure gauge 4 is higher than the pressure detected by the tank line pressure gauge 13 due to pressure loss caused by fluid resistance in the pipeline, the test target pressure P spec is determined as the pressure detection value of the pressure gauge 4 when the pressure detection value of the tank pipeline pressure gauge 13 becomes the required pressure in the test.

[0047] The total number of pressure increases N in the actual test is determined by the test start pressure P init Test target pressure P specThe test start pressure P is defined as the number of pressure rises divided by the pressure rise. init Test target pressure P spec This means that the pressure is increased in N steps up to the test start pressure P init If the process is executed directly after the preparation process S1, the initial pressure P init is the steady pressure P at the end of the preparation process test It becomes.

[0048] Furthermore, in the integrity test apparatus 1 of the present invention, the last boost out of the total number of boosts N is defined as a slight boost process, and the previous (N-1) boosts are defined as a coarse boost process. The rough boost process and the slight boost process respectively mean a process of boosting the voltage by a large boost amount and a process of boosting the voltage by a small boost amount. The rough boost process and the slight boost process will be described in detail in the actual test process S2. The slight boost process is defined as the last boost out of the total number of boosts N divided further into M times.

[0049] In the integrity test device 1, a rough pressure increase process and a fine pressure increase process are set, and in both processes, the pressure increase rate V p The test target pressure P spec Its distinctive feature is that it boosts the voltage to

[0050] The rough pressure increase time (the time that solenoid valve 3 is open) of each of the (N-1) rough pressure increase processes is T m Let us assume that T m is defined by the following equation (2). N.T. m =(P spec -P init ) / V p Therefore, T m =(P spec -P init ) / (N V p ) (2)

[0051] The time for each of the M times of the slight pressure increase process (the time that solenoid valve 3 is open) is T ad Let us assume that T adBe sure to check the pressure tolerance P of the test specification. tol Fits within T ad is defined by the following equation (3). T ad =t m P tol / (P test -P0) (3)

[0052] Here, P0,P test is the actual value during the preparation process, t m ,P tol is a given value. Pressure tolerance P tol For example, a predetermined tolerance value may be set above or below the target test value, and the upper or lower tolerance value that results in the target test value may be set to zero.

[0053] In all of the rough boost times (N-1) in the rough boost process and the fine boost times M in the fine boost process, when the solenoid valve 3 is closed, the delay time t d occurs, so in each of the (N-1) rounds of the rough boost process, T m +t d The time is T ad +t d The minimum time required is M times of the fine boost process. The M times of the fine boost process are allocated so as to correspond to one of N times of the coarse boost process.

[0054] The total boost time of the integrity test by the integrity test device 1 is the rough boost time T m The delay time t d Taking the above formula (2) into account, the total test time T test This can be calculated using equation (4). T test =N T m +{(N-1)+M}·t d =(P spec -P inti ) / V p +{(N-1)+M}·t d =(P spec -P inti )·t m / (P test -P0)+{(N-1)+M}·t d (4)

[0055] In order to make the integrity test by the integrity test device 1 more efficient, the total test time T test The total test time T test {(P spec -P test ) / V p} and t d The value of is determined by the integrity test equipment system 10, and N·T m The term (P spec -P test ) / V p Or (P spec -P init ) / V p Therefore, the total test time T test To make N the shortest possible value, this comes down to making the value of (N+M) the smallest possible.

[0056] The total number of boosts N is the preparation boost time t m and the rough pressure rise time T m is defined as a multiple of the ratio of N (T m / t m )=(P spec -P inti ) / (P test -P0) (5) Of these, P0,P inti ,P test is the measured value, t m ,P spec is a given value. Rough boost time T m is calculated as above. Therefore, N is calculated as the following formula (6). N=(t m / T m )·{(P spec -P inti ) / (Ptest -P0)}(6) The number of times M of the slight pressure increase process is the rough pressure increase time T m and the slight pressure rise time T of the slight pressure rise process, which is the opening and closing time of the solenoid valve 3. ad Using the above, it is defined as follows: M=T m / T ad (7)

[0057] (Determination of N and M) The total number of boosts N and the number of slight boosts M in the slight boost process are defined by the above definitions, but from these, N and M can be calculated specifically using the following method. First, M·N, the product of N and M, is given by the following equation (8). N M = (t m / T m )·{(P spec -P inti ) / (P test -P0)}·(T m / T ad ) =(P spec -P inti ) / P tol (8)

[0058] The total number of pressure increases N and the number of slight pressure increases M in the slight pressure increase process can be freely selected as long as they satisfy the above formula (8). In order to perform an integrity test of one membrane film in a short time, it is required to select the total number of pressure increases N and the number of slight pressure increases M in the slight pressure increase process so as to be minimum. Therefore, in the present invention, M and N are selected so that the total number of pressure increases N and the number of slight pressure increases M in the slight pressure increase process are minimum.

[0059] Boost speed V p , Rough boost time per time T m , T adUnder the above conditions, if the total number of boosts N and the number of minor boosts M in the minor boost process are appropriately selected, the total number of boosts N and the number of minor boosts M in the minor boost process (and the number of rough boosts (N-1) derived from these) will be the minimum number of times, and by performing boosts at the minimum number of times, the pressure tolerance P tol Test target pressure P spec The present invention is characterized in that the pressure can be increased to as high as 1000 psig.

[0060] That is, the right side of equation (8) (P spec -P inti ) / P tol is a constant obtained from the test of the preparation process, and the product MN of N and M is constant, so the total test time T test To minimize t d should be selected so that the coefficient of is smallest. T test =N T m +{(N-1)+M}·t d (9)

[0061] In other words, to determine N and M so that N and M are minimized, under the condition that the product MN of N and M is constant, they can be determined by selecting N and M for which the sum N+M of N and M is the smallest. There is not just one combination of M and N, but one can select one in which "the product MN of N and M is constant and the sum N+M of N and M is the smallest."

[0062] As a mathematical axiom, (N+M) / 2 ≥ (M N). 1 / 2 It is generally known that the minimum value of the sum of M and N is the minimum value of the product (M·N) of M and N. Therefore, in the integrity test equipment 1, the total number of boosts N, the number of coarse boosts N-1, and the number of fine boosts M are determined so that the product (M·N) of M and N becomes small.

[0063] For example, the test target pressure, P spec = 100 kilopascals (kPa), pressure tolerance P tol = 5 kilopascals (kPa), and the test start pressure P init= 55 kilopascals (kPa). In this case, N·M = 9 is derived from the above equation (8) as follows: M N = (P spec -P inti ) / P tol =(100-55) / 5 =9

[0064] And when N·M=9, it can be determined as follows. It can be determined as the combination of N and M when N·M=9. [Table 1] From this, the minimum value of the sum of N+M is M+N=6, and (M,N)=(3,3) can be determined (corresponding to Fig. 3). That is, in this case, the total number of boosts is 3, the number of slight boosts in the slight boost process is 3, and the number of coarse boosts is determined to be 2 (total number of boosts 3 - 1).

[0065] As another example, if N·M=16, it can be determined as follows. It can be determined as the combination of N and M when N·M=16. [Table 2] From this, the minimum value of the sum of N+M is M+N=8, and (M, N)=(4, 4) can be determined (not shown). In this case, the total number of boosts is 4, and the number of slight boosts in the slight boost process is 4, and the number of coarse boosts is determined to be 3 (total number of boosts 4-1).

[0066] Ideally, N and M are integers, but the product of N and M is determined by the time and pressure in the test system and is therefore a real number in practice, and N and M are also real numbers in practice. Also, M may be 1, but since N-1 is the number of times of the rough pressure increase process in which pressure is increased by a large amount, and the remaining pressure increase amount in the rough pressure increase process is M is the number of times of slight pressure increase in the slight pressure increase process in which pressure is increased by a small amount, it is preferable that M is 2 or more, and this is satisfied by the above.

[0067] In this case, N and M satisfy the following formula: N = M = (M N) 1 / 2 =[t m (P spec -P inti ) / (P test -P0) / {t m P tol / (P test -P0)}] 1 / 2

[0068] Also, at this time, T m satisfies the following formula: T m =T ad M =t m P tol ·√[(P spec -P inti ) / P tol ] / (P test -P0)

[0069] Setting the number of times of slight pressure increase in the slight pressure increase process to 1 is equivalent to making everything a rough pressure increase process. However, the slight pressure increase process is the final test target pressure P spec In the vicinity, the test target pressure P spec Since this is a process to gradually increase the pressure without exceeding the limit, it is meaningless to set M=1. Therefore, the number of slight pressure increases M must be greater than 1.

[0070] Ideally, N and M are integers, but N and M are the test target pressure P spec , Test start pressure P init , Pressure Tolerance P tol In most cases, N and M are not integers. If N and M are not integers (for example, if they have a decimal part), the rough boost time T m and the time T adEach of N and M is considered to be longer by a multiple of the quotient of the integer parts of N and M. In other words, each of N and M is defined as being longer by a multiple of the quotient of the integer parts of N and M. For example, in the case of M=3.3, the integer part of M=3.3 is 3, and the quotient is 1.1, and the slight boost time T ad is considered to be long, 1.1T ad This means that the slight boost is performed three times. The same applies to the number of times of rough boost (N-1). When the total number of boosts N is 4.3, the number of times of rough boost (N-1) is 3.3, the integer part of which is 3, and the quotient is 1.1. This is the part that shortens the rough boost time T m is considered to be long, 1.1T m In this way, even if N and M are not integers, the pressure tolerance P tol Test target pressure P spec The pressure can be increased up to

[0071] Furthermore, when N and M are not integers, a method can be used to omit the decimal parts of N and M. In other words, when N and M are not integers, integerization can be performed to obtain N and M so that they become integers. A representative method of integerization is to round up the fraction after the decimal point when determining at least one of N and M.

[0072] Since N and M are determined so that they are minimized, if N and M are not integers and N and M are converted to integers, the pressure tolerance P tol Test target pressure P spec In the present invention, the reason why N and M can be calculated by rounding up the decimal points of N and M is that, theoretically, the pressure tolerance P tol Test target pressure P spec Therefore, when N and M are rounded up to integers, the pressure tolerance P tol Test target pressure Pspec If N and M are reached, a boost cut-off process that cuts off boosting can be placed. In other words, one coarse boost is assigned to the fine boost, so the increase in coarse boost due to rounding up is always less than one, and in the worst case scenario, the fine boost is stopped when the fine boost is 0, making it possible to normally end the actual test process without exceeding the test pressure. In this way, when N and M are not integers, the decision-making load when determining N and M can be reduced by converting N and M to integers and placing a boost cut-off process.

[0073] For example, when N·M=7.84, M+N=5.6, N=M=2.8, so if N and / or M are rounded up to an integer, the number of coarse boosts (N-1)=2.8-1=1.8, which is rounded up to 2. The number of slight boosts in the slight boost process is M=2.8, so M=3 and the total number of boosts (M+N)=5.

[0074] The rounding up of the fraction after the decimal point may be performed in determining at least one of N and M. In other words, the rounding up of the fraction after the decimal point may be performed in determining both N and M or one of N and M. In particular, the rough boost time T m > Slow voltage rise time T ad Therefore, when determining the number of rough pressure increases (N-1), the decimal point is rounded up to make an integer, and N-1 is determined. When determining the number of fine pressure increases M, the decimal point is rounded down to make an integer, and if pressure increases are performed (N-1) times for the rough pressure increases and M times for the fine pressure increases, the pressure tolerance P tol Test target pressure P spec Even in this case, the pressure tolerance P tol Test target pressure P spec If the voltage reaches the threshold voltage, a boost cut-off process may be provided to cut off the boost.

[0075] The boost cut-off process is performed during boosting and the pressure tolerance P tol Test target pressure P specThis is a process for cutting off boosting when the total number of boosts N and the number of minute boosts M are determined. As described above, this process is required when at least one of N and M is rounded up to an integer in determining the total number of boosts N and the number of minute boosts M.

[0076] The boost cutoff process can be arranged not only to convert the total number of boosts N and the number of slight boosts M into integers, but also for the safety of the device. That is, the number of slight boosts M in the slight boost process is merely a planned number, and the test target pressure may be reached when the number of slight boosts in the slight boost process does not reach M due to an error in the boost value in each boost process. In particular, the number N-1 of the rough boost process and the number M of slight boosts in the slight boost process are determined based on the micro time t m Since it is calculated based on t m The smaller is the number of times, the more error is included in the calculation result. Therefore, when the number of times of slight pressure increase in the slight pressure increase process does not reach M, it is possible to set the pressure increase process to end when the test target pressure is reached, regardless of the number of times of slight pressure increase in the slight pressure increase process M as planned.

[0077] (Actual test process S2) The actual test process S2 will be described with reference to Figs. 2A, 2B and 3. The actual test process S2 is made up of a rough pressure increase process S21 and a slight pressure increase process S22. As described above, the actual test process S2 is performed at a test start pressure P init Test target pressure P, which is the test specification pressure spec The pressure is increased to the test start pressure P init can be the pressure of the main line 2 in any initial state of the integrity test device. Also, when the actual test process S2 is executed immediately after the preparation process S1, the test start pressure P init The steady pressure P test It can also be done like this.

[0078] For convenience, the total number of boosts N is set to 4. In this case, the number of coarse boosts N-1 in the coarse boost process is set to 3 (=4-1), and the number of minute boosts M is set to 3.

[0079] First, the pressure increase process is executed three times as the rough pressure increase process S21. In each rough pressure increase process, T m Solenoid valve 3 is opened only when T m After the solenoid valve 3 is closed, the delay time t d After a certain time, the pressure gauge 4 stabilizes from the unsteady value to a steady value. a1 ,P a2 ,P a3 , and the rough boosting process is completed.

[0080] Then, the voltage increasing process S22 is executed three times. In each voltage increasing process, the voltage increasing time T ad The solenoid valve 3 is opened for a slight pressure rise time T ad After the solenoid valve 3 is closed, the delay time t d After a certain time, the pressure gauge 4 stabilizes from the unsteady value to a steady value. f1 ,P f2 , the slight pressure increase process is completed, and the test target pressure P spec The pressure rises to

[0081] The boost rate V p is a constant proportional element, and the opening and closing time of the solenoid valve 3 determined by this (each rough pressure rise time T m and each slight pressure rise time T ad ), the total number of boosts N, the number of coarse boosts N-1 in the coarse boost process, the number of fine boosts M, and the delay time T dis determined. In theory, if the total number of boosts N determined by the above method, the number of coarse boosts N-1 in the coarse boost process, and the number of fine boosts M are used, the planned target test pressure will be reached in all boosts. However, depending on the actual state of the system, the test target pressure may be reached before the number of fine boosts M is reached. Therefore, even before the planned number of fine boosts M is reached, the test target pressure P spec When this is reached, boosting is terminated.

[0082] That is, the steady pressure P a1 ,P a2 ,P a3 , and the steady pressure P of the slight pressure increase process S22 f1 ,P f2 , each time, the test target pressure P spec Check that each pressure is not the test target pressure P spec Only when it is confirmed that the test target pressure P spec When it is confirmed that the pressure is not the test target pressure P spec If the pressure has reached this level, the pressure increase is stopped.

[0083] This allows the test target pressure P spec Therefore, even if the voltage boost control is based on a constant proportional element, it is possible to effectively perform voltage boost control safely and in a short time. [Explanation of symbols]

[0084] 1 Integrity Test Equipment 2 Main pipeline 3. Solenoid valve 4. Pressure gauge 5. Controller 10 Integrity Test Equipment System 11 Fluid source 111 Fluid source line 12 Sample Tank 12a Tank inlet port 121 Sample tank pipe 122 Tank discharge line 123 Inlet pipeline S sample 13 Tank line pressure gauge R1 Integrity Test Fluid Flow (Gas) R2 Fluid flow during plant operation (liquid)

Claims

1. A main pipeline is defined between an input port connected to a fluid source pipeline leading to a fluid source and an output port connected to a pipeline leading to a sample tank containing the sample, A solenoid valve is placed in the main pipeline and controls the opening and closing of the flow in the main pipeline, A pressure gauge for measuring the pressure in the main pipeline, The system includes a controller that performs the opening and closing control, and the sample is subjected to a test target pressure P spec A integrity testing apparatus for adding, The controller performs a preparation process and a practical test process. In the preparation process, the pressure gauge opens the solenoid valve to obtain an initial pressure P 0 and, after a predetermined preparation pressure increase time t m has elapsed, closes the solenoid valve. The steady pressure P at which the pressure fluctuation of the detected value of the pressure gauge after the closing of the solenoid valve subsides test and the delay time t test from the closing of the solenoid valve to the steady pressure P d are measured and input into the controller. The controller divides the pressure difference (P 0 −P test ) between the initial pressure P test and the steady pressure P 0 by the preparation pressure increase time t m to define it as the pressure increase speed V p . In the aforementioned test process, the boost rate V p The test start pressure P at the start of the actual test process. init From the aforementioned test target pressure P spec A integrity test apparatus for increasing the pressure of the aforementioned sample up to a certain point.

2. A integrity testing apparatus according to claim 1, The aforementioned test process comprises a rough pressure boosting process and M micro-pressure boosting processes. The aforementioned micro-pressure boosting process is defined by dividing the actual test process into a total of N pressure boosting cycles, and then dividing the last of the N total pressure boosting cycles into M micro-pressure boosting cycles. The aforementioned rough pressurization process is defined by an integrity testing apparatus with N-1 rough pressurization cycles performed before the aforementioned micro pressurization process.

3. The integrity testing apparatus according to claim 2, The aforementioned test start pressure PP init From the aforementioned test target pressure P spec Up to the aforementioned boosting speed V p The time obtained by dividing by the total number of pressure boosts N is divided by the total number of pressure boosts N to obtain the rough pressure boost time T per boost. m It was defined as, The aforementioned rough pressure increase time T m Divide this by the number of slight pressure increases M times to obtain the slight pressure increase time T per instance. ad It was defined as, The rough pressurization process includes the rough pressurization time T for each of the N-1 rough pressurization cycles. m The voltage is boosted, The aforementioned slight pressure boosting process has a slight pressure boosting time T for each of the M slight pressure boosting cycles. ad A integrity testing device that uses a boosting voltage.

4. The integrity testing apparatus according to claim 3, The product of the total number of pressure increases N times and the number of slight pressure increases M times is the target test pressure P. spec From the aforementioned test start pressure P init The value obtained by subtracting this is the predetermined pressure tolerance P for the test specification. tol Divided by M・N = (P spec -P inti ) / P tol It was defined as, A integrity testing apparatus in which the number of slight pressure increases M times and the total number of pressure increases N times are determined such that the sum of the number of slight pressure increases M times and the total number of pressure increases N times is minimized.

5. A integrity testing apparatus according to claim 4, If the total number of boost cycles N and the number of micro-boosting cycles M are not integers, the rough boosting time T is set for each of N and M. m and the aforementioned slight pressure increase time T ad A integrity test apparatus defined by each of the following being a multiple of the quotient of the integer parts of N and M.

6. A integrity testing apparatus according to claim 4, A integrity testing apparatus that, when the total number of pressure boosts N and the number of slight pressure boosts M are not integers, performs integer determination by treating each of the total number of pressure boosts N and the number of slight pressure boosts M as integers.

7. A integrity testing apparatus according to claim 6, The integerization refers to a integrity test apparatus in which the fractional part of the decimal part is rounded up when determining at least one of the total number of voltage boosts N times and the number of slight voltage boosts M times.

8. A integrity testing apparatus according to any one of claims 1 to 7, During the aforementioned pressure increase, the target test pressure P spec A integrity test apparatus equipped with a boost cutoff process that cuts off the boost when a certain threshold is reached.

9. A fluid source and A fluid source pipeline leading to the aforementioned fluid source, A sample tank containing the sample, The pipeline leading to the aforementioned sample tank, A integrity testing apparatus system comprising an integrity testing apparatus, The aforementioned integrity testing apparatus is, A main pipeline is defined between an input port connected to the fluid source pipeline and an output port connected to the pipeline leading to the sample tank, A solenoid valve is placed in the main pipeline and controls the opening and closing of the flow in the main pipeline, A pressure gauge for measuring the pressure in the main pipeline, The system includes a controller that performs the opening and closing control, and the sample is subjected to a test target pressure P spec A integrity testing apparatus for adding, The controller performs a preparation process and a practical test process. In the preparation process described above, the solenoid valve is opened using the pressure gauge to achieve an initial pressure P 0 Then, a predetermined preparation and boosting time t m After the specified time has elapsed, the solenoid valve is closed, and the steady-state pressure P of the pressure reading detected by the pressure gauge after the closing of the solenoid valve settles down. test Then, from the closing of the solenoid valve, the steady-state pressure P test The delay time t until it reaches that point d The controller measures and acquires the initial pressure P, and the controller then processes the initial pressure P. 0 and the steady-state pressure P test The pressure difference of the increment (P test -P 0 ) during the aforementioned preparation and boosting time t m Divide by the boost rate V p It was defined as, In the aforementioned test process, the boost rate V p The test start pressure P at the start of the actual test process. init From the aforementioned test target pressure P spec A integrity testing apparatus system for increasing the pressure of the aforementioned sample up to a certain point.

10. A integrity testing apparatus system according to claim 9, The aforementioned test process comprises a rough pressure boosting process and M micro-pressure boosting processes. The aforementioned micro-pressure boosting process is defined by dividing the actual test process into a total of N pressure boosting cycles, and then dividing the last of the N total pressure boosting cycles into M micro-pressure boosting cycles. The aforementioned rough pressurization process is defined by the number of rough pressurization cycles N-1 performed before the aforementioned fine pressurization process in the integrity testing apparatus system.

11. A integrity testing apparatus system according to claim 10, The aforementioned test start pressure PP init From the aforementioned test target pressure P spec Up to the aforementioned boosting speed V p The time obtained by dividing by the above is divided by the total number of pressure boosts N times to define the rough pressure boost time Tm per boost. The rough pressure increase time Tm is divided by the number of micro-pressure increases M times to obtain the micro-pressure increase time T per increase. ad It was defined as, The rough pressure boosting process is performed by boosting the pressure for the rough pressure boosting time Tm in each of the N-1 rough pressure boosting cycles. The aforementioned slight pressure boosting process has a slight pressure boosting time T for each of the M slight pressure boosting cycles. ad A integrity testing apparatus system that uses a boosting voltage.

12. A integrity testing apparatus system according to claim 11, The product of the total number of pressure increases N times and the number of slight pressure increases M times is the target test pressure P. spec From the aforementioned test start pressure P init The value obtained by subtracting this is the predetermined pressure tolerance P for the test specification. tol Divided by M・N = (P spec -P inti ) / P tol It was defined as, A integrity testing apparatus system in which the number of micro-pressure boosts M times and the total number of pressure boosts N times are determined such that the sum of the number of micro-pressure boosts M times and the total number of pressure boosts N times is minimized.

13. A integrity testing apparatus system according to claim 12, If the total number of boost cycles N and the number of micro-boosting cycles M are not integers, then for each of N and M, the rough boosting time Tm and the micro-boosting time T ad A integrity testing apparatus system defined by each of the following being a multiple of the quotient of the integer parts of N and M.

14. A integrity testing apparatus system according to claim 12, A integrity testing apparatus system that, when the total number of pressure boosts N and the number of slight pressure boosts M are not integers, performs integer determination in which the total number of pressure boosts N and the number of slight pressure boosts M are determined to be integers.

15. A integrity testing apparatus system according to claim 14, The integerization refers to a integrity test apparatus system in which the fractional part of the decimal part is rounded up when determining at least one of the total number of voltage boosts N times and the number of slight voltage boosts M times.

16. A integrity testing apparatus system according to any one of claims 9 to 15, During the aforementioned pressure increase, the target test pressure P spec A integrity test apparatus system equipped with a boost cutoff process that cuts off the boost when a certain threshold is reached.

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