JPH07275621A - Method and apparatus for estimating degree of clogging of filter as well as method for judging clogging - Google Patents

Abstract

PURPOSE:To estimate the degree of clogging rationally by calculating a proper variable as a scale indicating the degree of the clogging of a filter, by calculating the variable under installing a filter in a channel. CONSTITUTION:A processor 7 obtains a flow rate signal of fluid to be filtered from a flow meter 5 during the continual operation, reads the absolute viscosity of the fluid to be filtered and the pressure difference between the inlet and outlet of the filter, and obtain the values respectively from an absolute viscosity sensor 4 and a pressure difference meter 6. The processor 7 calculates the absolute value of a variable indicating the degree of clogging of the filter according to the read values of the flow meter 5, the sensor 4, and the pressure difference meter 6, inputted signals inputted from a keyboard or the read values of the sizes of the elements of the filter 1 which are stored in advance in a memory 12 or is actuated according to an algorithm for estimating the result whether the variable indicating the degree of clogging is too high, too low, or acceptable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for estimating the degree of clogging of a strainer having a rectangular cross section such as a rectangle, a square or a trapezoid, a device therefor, and a method for determining the clogging state.

[0002]

2. Description of the Related Art Strainers having passages of rectangular, square, trapezoidal, parallelogram, other quadrilateral and so-called rectangular cross-sections are used as full strainers for engine oil circulation systems of marine diesel engines or for industrial use. Widely used as a strainer for gas or liquid. The typical shape and dimensions of the fluid passage to be processed by such a strainer are as shown in FIG.
The cross section is rectangular, and the short side, long side, and passage length are 50μ each.
m, 3 mm, 0.7 mm, which is a thin and long passage, and a large number of such passages are arranged on the cylindrical surface,
Forming a strainer.

It is desirable that the degree of clogging of a strainer having a passage having a rectangular, square, or trapezoidal sectional shape as described above is expressed as a measured numerical value. It is possible to know exactly from the measured value what the mechanical condition of the strainer having the rectangular cross-sectional shape is,
For example, when the degree of clogging rises above a certain level, cleaning, washing or maintenance can be performed accurately.

The degree of clogging based on the measured value is useful for accurately predicting that the possibility of being in the usable area until the next cleaning, cleaning or maintenance is sufficient. Further, the variable representing the degree of clogging can be predicted in the future by a rational method such as extrapolation of the increase up to that point in the future.

However, conventionally, the degree of clogging of the strainer is
With the strainer removed from the flow channel used, it is possible to measure semi-quantitatively by observing with a microscope using transmitted light illumination, but generally the numerical value of the degree of clogging of the strainer, It was difficult to calculate the strainer installed in the flow path and in use.

[0006]

On the other hand, there is also a method in which the increase value of the differential pressure between the inlet and the outlet of the strainer is used as a scale indicating the degree of clogging of the strainer, but the increase value of the differential pressure is If the absolute viscosity of the fluid to be processed and the dimensions of each part of the strainer change,
Even if the flow rate of the filtered fluid is constant, it does not show a change corresponding to the degree of clogging, and is not appropriate as a scale indicating the degree of clogging of the strainer.

In view of the above conventional circumstances, the present inventors have determined that the pressure difference between the inlet and outlet of the strainer is constant with respect to the dimensions of each strainer, the flow rate of the filtered fluid, and the degree of clogging. In the case of, the present invention was found to be proportional to the absolute viscosity of the processing fluid, and based on this finding, the present invention installed a strainer in the flow passage as an appropriate variable as a measure of the degree of clogging of the strainer. The purpose is to calculate in use conditions, reasonably estimate the degree of clogging, and determine the clogging condition.

[0008]

Therefore, according to the invention described in claim 1, the differential pressure between the inlet part and the outlet part of a strainer having a fluid passage having a rectangular cross section, and the absolute value of the fluid to be treated by the strainer A method of estimating the clogging degree by calculating a variable indicating the degree of clogging of the strainer from the viscosity, the size of each part of the strainer, and the flow rate of the filtered fluid.

According to a second aspect of the present invention, there is provided means for outputting differential pressure information between an inlet and an outlet of a strainer having a fluid passage having a rectangular cross section, and absolute viscosity information of a fluid processed by the strainer. An output means, a means for outputting dimension information of each part of the strainer, a means for outputting flow rate information of the filtered fluid, and a clogging degree of the strainer based on each signal output from each of the output means. A clogging degree estimation device for a strainer configured to include a means for calculating a variable.

The invention according to claim 3 is acceptable based on the differential pressure between the inlet and the outlet of a strainer having a fluid passage having a rectangular cross section and the absolute viscosity of the fluid to be treated in the strainer. A storage means in which a large clogging area and an unacceptable clogging area are assigned in advance, and which area of the two areas is referred to based on the actual differential pressure and absolute viscosity with reference to the storage means The method for determining the clogging of the strainer is to determine if

[0011]

In the invention according to claim 1, the variable representing the degree of clogging is determined from the differential pressure between the inlet and outlet of the strainer, the absolute viscosity of the treatment fluid, the dimensions of each portion of the strainer, and the flow rate of the filtered fluid. It is possible to accurately know the mechanical state of the strainer having a passage having a rectangular cross-sectional shape from the calculated variable indicating the degree of clogging. When rising above the size, cleaning, washing or maintenance can be performed properly.
In addition, the degree of clogging by the calculated variable is an expected value due to extrapolation extension in the near future of the increasing change up to that point, and this degree of clogging is within the usable range until the next cleaning, cleaning or maintenance. It is useful for accurately predicting that the possibility is sufficient.

According to the second aspect of the present invention, it becomes easy to calculate the numerical value (variable) of the degree of clogging of the strainer in a use state in which the strainer is installed in the flow path. In the invention according to claim 3, the clogging of the strainer can be determined simply by determining the regions corresponding to the values of the actual differential pressure and the absolute viscosity, and the determination of the clogging can be performed very simply and conveniently. Therefore, the clogging state of the strainer can be accurately known, and cleaning, washing or maintenance can be accurately performed.

[0013]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. First, the concept and outline of the method of the present invention will be described. The differential pressure between the inlet and outlet of a strainer having a rectangular cross-section is conventionally analyzed as the product of the pressure loss coefficient and the dynamic pressure of the strainer as a whole, which was experimentally obtained, and Analysis or estimation that quantitatively considers dimensions and degree of clogging has not been performed.

As a result of extensive research conducted by the present inventors on this point, the differential pressure between the inlet and outlet of a strainer having a passage having a square cross-section is determined by viscous friction pressure loss of a rectangular cross-section line, cylinder and the like. Of the viscous friction pressure loss of a group of pipes or a group of circular pipes and the pressure loss due to the bending and cross-sectional area change of the strainer element inlet / outlet due to the strainer container, and if it is analyzed or estimated, it should be in good agreement with the actual value. I found out.

The viscous frictional pressure loss of the rectangular cross-section conduit is described in the following documents 1-3. Reference 1: Irvine, Jr. , T. F. and Ha
rtnett, J .; P. , (Ed), Advances
in Heat Transfer, Supplem
ent 1, (1978), 196, Academic
Press. Reference 2: Japan Society of Mechanical Engineers Mechanical Engineering Handbook (new edition) A5
(1986) 76, formula (252) Reference 3: Chemical Engineering Association Chemical Engineering Handbook (Revised 5th Edition) (1
988), 265, formula (5/20) Further, the viscous friction pressure loss of the group of cylinders or the group of pipes is described in the following Documents 4 and 5.

Reference 4: Gunter, A. et al. Y. and
Shaw, W.C. A. Trans. ASME, 67 (1
945-11) 643 Reference 5: Chemical Engineering Society Chemical Engineering Handbook (Revised 5th Edition) (1
988), 277, formula (5.129), formula (5.13)
0) The invention according to claim 1 based on such knowledge is based on the differential pressure between the inlet and the outlet of the strainer, the absolute viscosity of the treatment fluid, the dimensions of each portion of the strainer, and the flow rate of the filtered fluid. A method of calculating a variable indicating the degree of clogging is used.

Further, in this embodiment, the number of clogging particles is calculated as one of the variables. The number of clogging particles is a value obtained by approximating the number of cylinders or circular tubes approximate to the group of cylinders or circular tubes to the number of particles. As one of the variables, in addition to the number of clogging particles, a gap between the clogging particles, or a long side length of a rectangular cross-sectional path that is considered to be shortened due to clogging may be calculated. good. Furthermore, the absolute value of the calculated variable may be used instead of the calculated variable.

In the method of the present invention, by using the variable representing the degree of clogging, the future prediction of the degree of clogging or the future prediction of the differential pressure can be rationalized based on the concentration of clogging particles or objects in the filtered fluid. It is possible depending on the estimation method. That is, the variable that represents the degree of clogging is the expected value due to extrapolation extension in the near future of the increase transition up to that point, and this degree of clogging can be in the usable area until the next cleaning, cleaning or maintenance. This is useful for accurately predicting that sex is sufficient.

Therefore, if the differential pressure in a state without clogging under a certain filtration condition is known, a value indicating the degree of clogging under the filtration condition to be estimated can be calculated. in this case,
In practice, the filtration conditions do not remain constant, and therefore an estimation formula of the clogging differential pressure including each variable of the filtration conditions and / or the variable of the size of each part of the strainer is used.

The formula for estimating the clogging differential pressure was designed as the sum of the three terms. The first term given below is the friction loss of the rectangular cross-section passage. As the pipe friction coefficient, the analytical solution in the case of laminar flow is omitted here because the second and subsequent terms are small. Of course, it is also possible to use without omitting.

[0021]

[Equation 1]

The second term shown below is pressure loss due to bending of the flow in the inlet / outlet passage of the strainer, change in cross-sectional area, etc., and is due to the product of dynamic pressure and loss coefficient.

[0023]

[Equation 2]

The third term shown below is a friction loss obtained by approximating clogging particles with the group of cylinders shown in FIGS. 1 (A) and 1 (B), and the applicable range is as low as Reynolds number less than 100, The column spacing is about 1.25 to 5 times the column diameter, and is a formula for a relatively long range.

[0025]

[Equation 3]

The details of one example of the cylinder group approximation in using the expression of the third term are the following assumptions. (1) Particles can be approximated by a cylinder. (2) The diameter of the cylinder is 50 μm. (3) The axis of the cylinder is parallel to the short side direction.

(4) The columns are staggered in two rows. (5) Captured at equal intervals. (6) The spacing in the flow direction of the column of columns is 50 μm. (7) As for the cylinders at both ends in the direction perpendicular to the flow in the first row, semi-cylinders divided by a plane including the cylinder axis and the flow direction are adhered and captured on the end faces at the ends in the direction perpendicular to the flow.

(8) The definition of how to count the number of particles is as follows: in the case of only two semi-cylinders at both ends of the first row, one in the first row, one in the second row,
I decided to count it as two in total. 1 between the semi-cylinders in the first row
When two pieces were added to the first row, two pieces were added to the second row, and a total of four pieces was defined. When the first column increases by one, the total number increases by two. The number in the first column is N in the formula. In the above description, it is particularly emphasized that the number of particles can be estimated for the first time by approximating the number of cylinders, which is not the number of particles, as the number of particles.

The diameter of the cylinder of the above assumption (2) is
The range may be 5 to 200 μm (preferably 20 to 70 μm). Further, the above-mentioned hypothetical (4) staggered row may be in the range of 2 to 7 rows (preferably 2 to 5 rows). Furthermore, the above-mentioned assumption (6), the spacing in the flow direction of the column of cylinders, may be in the range of 5 to 200 μm (preferably 20 to 70 μm), and is set to a value equal to the diameter of the column of (2). preferable.

The formula for estimating the clogging differential pressure is the sum of the above three terms and is as follows.

[0031]

[Equation 4]

However, in the above equation, Δp: total pressure loss A: correction coefficient of pipe friction coefficient ρ: density of fluid ν: kinematic viscosity of fluid l ₁ : length of rectangular section pipe line bL: column spacing of columns (Flow direction) Q: Volume flow rate n: Number of openings a: Long side length of cross section of rectangular pipe line b: Short side length of cross section of rectangular pipe line F: Cross sectional area of outlet pipe inner diameter d ₀ : Diameter of cylinder B : Pressure loss coefficient due to size, shape, bend, etc. of flow passage cross section Rev: Reynolds number = dv x u / v dv: 4 (space volume in cylinder group) / (external surface area of cylinder)
^{_{= 4 (bTbL-πd 0 2}} /4) / (πd 0) u: mean velocity = Q / [(bL'-d ₀₎ of the fluid at the minimum flow passage cross section (the gap between the clogging particles) bn (2N + 2 )] bT: spacing cylinder (flow perpendicular) = a / (N + 1 ) bL': diagonal spacing of the columnar = ^{[bL 2 + (bT / 2)} 2 ]
^0.5 N: Number of cylinders in the 1st row of the cylinder group (in the rectangular section pipeline, passage 1
Number of particles per particle) l ₂ : Length of cylinder group = bL × (Number of columns in flow direction of cylinder group: 2 in this example) If the differential pressure estimation formula described above is used, the number of clogging particles N
Can be given to calculate the differential pressure.

On the contrary, if the measured differential pressure is given, the number N of clogging particles as a variable indicating the degree of clogging can be calculated. In this case, the number of particles is calculated so that the calculated differential pressure approaches 0.2% of the measured differential pressure by repeating the trial and error of calculating the differential pressure assuming the number of clogging particles.

It should be noted that the actually measured differential pressure may be applied to calculate the gap between the clogging particles in the minimum flow path cross section as a variable indicating the degree of clogging. Alternatively, if the differential pressure at the start of clogging differs from the estimated value obtained by the sum of the first and second terms of the equation, the long side length of the passage is corrected to estimate the clogging differential pressure. calculate. According to this method, the following variables can be calculated. This is equivalent to calculating the long side length of a rectangular cross-section passage, which is considered to be shortened due to clogging, as one of the variables indicating the degree of clogging in the case of a strainer having a rectangular cross-section fluid passage. To do.

The first and third terms of the differential pressure estimation formula described above are not limited to the above-mentioned contents, but are described in another document,
For example, the first term is set based on the formula described in the following reference 6, and the third term is set in the following reference 7
The setting may be made based on the formula described in, or another appropriate formula may be used. Reference 6: Takesuke Fujimoto, Introduction to hydraulics, (3rd edition), (195
5), 82, formula (4.2), formula (4.3) and 71,
Formula (1.2), Yokendo Reference 7: Chemical Engineering Association, Chemical Engineering Handbook (Revised 5th Edition),
(1988), 277, formula (5.124), formula (5.
125), Expression (5 · 126) Next, an experiment conducted by the present inventors in examining the differential pressure estimation expression will be described.

The first experiment is an experiment of a strainer without clogging, the second experiment is an experiment in which the clogging element recovered particles of an actual machine are put into a circulating oil passage system, and the third experiment is an experiment of an actual machine. It is a one-time oiling experiment of the used oil that has clogged. still,
The dimensions and flow velocity of the rectangular cross-section passage of the strainer used in the experiment should be the same as the actual machine. In this respect, it is not a similar experiment but a full-scale experiment. An element or a container having a small scale was used.

As the sample oil, A oil, B oil, and C oil were used.
The oils A and B are clean, unused oils, and the oil C is the oil that has been clogged in the actual machine. The SAE Nos. Of oils A, B, and C are 40, 30, and 40, respectively. As the oil passage device, a circulating oil passage system and a single oil passage system in which the oil temperature and the flow rate were maintained were used. In the first and third experiments, the measurement of the differential pressure was detected by the composite semiconductor sensor and recorded by the pen recorder. Second
In the experiment, the differential pressure was measured with a Bourdon tube pressure gauge.

The first experiment will be described. In order to obtain the coefficient A of the first term and the coefficient B of the second term in the differential pressure estimation formula, the differential pressure is actually measured by a strainer having no clogging. For the measurement of the differential pressure, a small strainer A, a clean unused oil A oil, and a circulating oil passage system were used.

The measured differential pressure by changing the oil temperature, that is, the absolute viscosity is as follows. Oil temperature ° C Absolute viscosity kg / ms Actual measured differential pressure kPa 40 0.1496 61.5 50 0.0880 37.0 60 0.0552 25.0 As a result of regression calculation using this value, the coefficient A is 1. 155
14, the coefficient B was 200.785.

It can be seen that the estimated value and the actually measured value by the coefficient thus obtained, for the strainer A, are in good agreement as seen in FIG. As a result, the first differential pressure estimation formula
It can be seen that the term and the second term well represent the relationship of each factor of the strainer without clogging. Next, the second experiment will be described.

This is the first case where the differential pressure estimation formula was examined in a system with clogging. The particles collected from the actual device clogging element were put into a circulating oil passage system, and the change in differential pressure with time was measured. The particles for charging were unwound from the element coil of the strainer clogged with an actual machine and collected by a wire net having an opening of 44 μm.

A large strainer B, clean virgin oil B oil, and a circulating oil system were used. A Bourdon tube pressure gauge was used to detect the differential pressure. The change in the differential pressure with respect to the number of circulations is shown in FIG.
About 1 mg of recovered particles was intermittently charged every 5 apparent cycles.

The measurement of the differential pressure is performed after the apparent circulation number after charging, about every 5 times, after 99% or more of the charged particles are captured. The meaning when the apparent circulation number is 5 times means the time when the amount of oil passing through the strainer reaches five times the amount of oil that has passed in. Approximately 45 hours in the amount of 5.8L oil
Equivalent to minutes.

The following three facts obtained from the change of the differential pressure with respect to the number of circulations show that the differential pressure estimation formula well represents the relationship of each factor of the clogging differential pressure. First
The facts of are as follows. The number of particles corresponding to the actually measured differential pressure has a linear relationship with the cumulative value of the mass of the input particles (see FIG. 4). This shows that the increase of the two values corresponds to a constant ratio. This constant ratio correspondence means that the mass of one particle is almost constant. Since the particle size is almost constant, this is in agreement with the fact that particles having a substantially uniform density were added.

The regression line is calculated based on the differential pressure portion due to clogging in the differential pressure, that is, the value at the time when the third term is large and the variation in the estimated particle number is small. The second fact is as follows. The mass of one particle is known from the constant ratio correspondence of the number of particles corresponding to the measured differential pressure and the cumulative value of the input particle mass, and based on this, the apparent density of particles assuming a diameter of 50 μm is 3.2.
It is estimated to be 0 g / cm ³ . This value is close to 2.32 g / cm ³ of 2.25 g / cm ^3, calcium sulfate dihydrate which is the composition of the particles of graphite.

The third fact is as follows. It can be seen in FIG. 5 that the number of particles corresponding to the measured differential pressure has a linear relationship with the number of circulations. This is consistent with the fact that the particles were injected at a constant speed. The presence of the Y intercept in the regression line in FIG. 5 is considered to be due to the initial stain of the oil passage system and the bias of the zero point of the differential pressure measurement system.

Further, when the differential pressure is estimated by giving the number of particles by the regression line to the differential pressure estimation formula, it is clear from FIG. 6 that the measured differential pressure agrees well. Next, the third experiment will be described. This is the second case of studying the differential pressure estimation formula in a system with clogging. The change with time of the differential pressure was measured in a single oil passage experiment of the oil used that caused clogging in the actual machine. In this case, a small strainer A is used.

The measured differential pressure is shown in FIG. The following two facts obtained from the change with time of the differential pressure indicate that the differential pressure estimation formula well represents the relationship between the factors of the clogging differential pressure. The first fact is as follows. It is clear from FIG. 8 that the number of particles corresponding to the measured differential pressure shows a linear relationship with the oil passage time. This indicates that the concentration of particles that clogged up was in agreement with the fact that a constant flow rate of oil was fed.

The fact that this regression line has a Y-intercept means that
This is probably due to the initial contamination of the oil passage system and the bias of the zero point of the differential pressure measurement system. Further, when the differential pressure is estimated by giving the number of particles by the regression line to the differential pressure estimation formula, it is clear from FIG. 9 that the measured differential pressure agrees well. The second fact is as follows.

The slope of the regression line of the number of particles corresponding to the measured differential pressure to the oil passage time shown in FIG. 8 gives the number concentration of particles in oil.
Based on this, assuming that the particle size is 50 μm and the particle density is 2.32 g / cm ³ of calcium sulfate dihydrate, the mass concentration of the particles in oil can be estimated as follows. When the oil temperature is 50 ° C 0.198 ppm When the oil temperature is 53 ° C 0.150 ppm When the oil temperature is 56 ° C 0.159 ppm Measured value 0.195 ppm And these estimated values are the measured concentrations 0.195 ppm
It can be seen that it substantially matches with.

This is the end of the description of the experiment. still,
Applying the estimation formula of the clogging differential pressure, the following can be considered. That is, when the increase in the number of clogging particles with respect to the oil passage time shown in FIG. 8 is equal to the regression line of 56 ° C., the differential pressure increase due to the increase in absolute viscosity is shown in FIG. Get faster as shown.

Therefore, when the degree of clogging is the same,
It can be seen that in order to carry out cleaning, it is necessary to increase the differential pressure that determines the cleaning time in accordance with the increase in absolute viscosity. still,
This will be described in an application example described later. As described above, it is apparent that the clogging differential pressure estimated by the differential pressure estimation formula designed by the present inventors is in good agreement with the fact.

Therefore, if the differential pressure estimation formula described above is used,
By giving the measured differential pressure, it is possible to calculate the clogging particle number N or the like as a variable indicating the clogging degree, and it is possible to determine the cleaning time from the clogging particle number N or the like. Next, an embodiment of the invention device according to claim 2 for carrying out an embodiment of the method for estimating the degree of clogging of a strainer according to the invention described in claim 1 will be described.

This apparatus comprises means for outputting differential pressure information between the inlet and outlet of a strainer having a fluid passage having a rectangular cross section, and means for outputting absolute viscosity information of the fluid processed by the strainer. , A means for outputting the dimension information of each part of the strainer, a means for outputting the flow rate information of the filtered fluid, and a variable representing the degree of clogging of the strainer based on the signals output from the output means And means.

As a concrete example of such a clogging degree estimating device, an automatic measuring system for variables representing the clogging degree as shown in FIG. 11 can be considered. That is, in the figure, the strainer 1 is interposed between the inlet pipe 2 and the outlet pipe 3, and the filtered fluid is pressure-fed from the inlet pipe 2 to the strainer 1. The degree of clogging of the strainer 1 is reduced by cleaning the elements of the strainer 1, for example, backwashing, high pressure air jet or ultrasonic cleaning, and is increased by continuing filtration of the filtered fluid. During continuous operation, the processor 7 obtains a flow rate signal of the filtered fluid from the flow meter 5 as a flow rate information output means of the filtered fluid, and reads the absolute viscosity of the filtered fluid and the differential pressure between the inlet and outlet of the strainer 1. From the absolute viscosity sensor 4 as the absolute viscosity information output means and the differential pressure gauge 6 as the differential pressure information output means.

It is necessary that the time interval for obtaining all the readings is sufficiently shorter than the cleaning interval of the strainer 1 and not too short in comparison with the changing speed of each variable to be read. This interval varies depending on the design of the filtration system and the situation of contamination with dirt that causes clogging. The processor 7
Is a flow rate meter 5 of the filtered fluid interposed in the inlet pipe 2.
Similarly, the reading from the differential pressure gauge 6 installed in the bypass pipe 20 that bypasses the absolute viscosity sensor 4 and the strainer 1 also installed in the inlet pipe 2 and connects the inlet pipe 2 and the outlet pipe 3, and the keyboard 11 The absolute value of the variable indicating the degree of clogging of the strainer 1 is calculated according to the signal output from the device or the reading of the value of the size of each part of the element of the strainer 1 that is stored in the storage device 12 in advance. It operates according to an algorithm that infers the conclusion that the variable representing the degree of clogging is too high, too low, or acceptable.

That is, the processor 7 has a function of means for calculating the absolute value of a variable indicating the degree of clogging and a function of means for determining the clogging state based on the calculated absolute value of the variable for indicating the degree of clogging. In addition to the above, the determination result of the determination means is remote from the display light of the instrument panel 21 attached to the processor 7, an alarm device such as a buzzer, the notification devices 8 to 10 and 18 such as a CRT device, or the processor 7. It has a function of outputting to an indicator light of an external device, an alarm device such as a buzzer, and an alarm device 22 to 25 such as a CRT device.

When the variable indicating the degree of clogging is too low, the processor 7 outputs the strainer failure notification signal a to the notification device 22 and causes the notification device 22 to perform the strainer failure notification. Alternatively, the strainer failure notification device 8 (for example, strainer failure display light) of the instrument panel 21 is operated (lighted) to warn the user to stop the operation.

If the variable indicating the degree of clogging is acceptable and is sufficiently low for the continuation of the operation, the processor 7 outputs a strainer-acceptable notification signal b to the notification device 23 to notify the notification. Strainer failure notification is performed by the device 23, or the strainer acceptability notification device 9 of the instrument panel 21
(For example, a strainer-acceptable display light) is operated (lit) to notify the user that there is no problem in driving.

If the variable indicating the degree of clogging is too high, the strainer 1 is operating outside the normal limits, or the filtered fluid flow meter 5, the absolute viscosity sensor 4 and / or the differential pressure meter 6 is used.
Is giving an incorrect reading to the processor 7 for some reason. If the flow meter 5 of the filtered fluid, the absolute viscosity sensor 4 and / or the differential pressure gauge 6 gives an incorrect reading, the reading is reread and the reading is rarely given again.

Accordingly, the processor 7 causes the filtered fluid flow meter 5, the absolute viscosity sensor 4 and / or the differential pressure gauge 6 to obtain new readings and again operates using the same algorithm based on these readings. . This new result
When there are too few variables indicating the degree of clogging, the processor 7 performs the above-described operation to output the failure notification signal a or operate (turn on) the strainer failure notification device 8 (for example, the strainer failure display light). To do.

If the new result is acceptable, the output of the acceptable notification signal b or the operation (lighting) of the strainer-acceptable notification device 9 (for example, the strainer-acceptable indicator light) is performed. To do. If the new result is that the variable indicating the degree of clogging is too high again, the processor 7 outputs an instrument failure or excessive clogging notification signal c to the notification device 24, and the notification device 24 is notified to the notification device 24. User to use the strainer 1 by performing an instrument failure or an excessive clogging notification or by operating (turning on) an instrument failure or an excessive clogging notification device 10 (for example, a display light) on the instrument panel 21. Warn to stop continuing.

If the variable indicating the degree of clogging is acceptable, but is higher than a preset value, or if the increase tendency stored up to that point in the storage device 12 up to that point is outside the near future. If the estimated value exceeds the allowable limit for continuous use by the time of the next variable measurement indicating the degree of clogging, backwashing or element extraction cleaning, the processor 7 indicates that the variable indicating the degree of clogging is the time when the next treatment is scheduled. A signal d indicating that the limit has been exceeded is output to the notification device 25, and the notification device 25 is informed of the limit being exceeded before the next scheduled treatment time, or the limit is exceeded before the next treatment time. The notification is given by operating (lighting) the limit excess notification device 18 (for example, an indicator light) of the instrument panel 21, and a message indicating that the limit will be exceeded before the next scheduled treatment time. Recording the over-di signal e in the storage device 12. The strainer user calls the message signal e from the storage device 12 to the notification device in a timely manner to know that the limit will be exceeded before the next scheduled treatment time notified by the notification device, or the instrument panel 21 Appropriate treatment is performed before the next scheduled treatment time by looking at the operation (lighting) of the limit excess notification device 18 (for example, the display light) or by hearing the notification by the notification device 25, for example, a remote alarm sound.

Such a system uses an appropriate algorithm, and outputs the result of this algorithm to many informing devices of the instrument panel or an informing device of an external device by outputting signals electrically, magnetically and optically. Alternatively, the strainer user may be configured to give a variable indicating the actual degree of clogging by recording the same in a storage device. In such a configuration, the value indicating the limit of the variable indicating the degree of clogging at which the cleaning should be performed may be changed due to some other parameters such as the fluctuation of the inflow amount of dirt, the cleaning removal accuracy, or the limit of the cleaning frequency. Preferred when changing.

According to the embodiments of the invention described in claims 1 and 2 described above, it becomes easy to calculate the numerical value of the degree of clogging of the strainer in a use state in which the strainer is installed in the flow path, Calculated from the differential pressure between the inlet and outlet of the strainer, the absolute viscosity of the processing fluid, the dimensions of each part of the strainer, and the flow rate of the filtered fluid. It is possible to accurately know what the mechanical condition of the vessel is, for example, to perform cleaning, washing or maintenance accurately when the degree of clogging rises above a certain size. it can.

Further, it is possible to accurately predict that there is a sufficient possibility that the degree of clogging by the calculated variables will be in the usable area until the next cleaning, cleaning or maintenance time. That is, the degree of clogging by the calculated variable is an expected value due to extrapolation extension in the near future of the increasing transition up to that point, and this degree of clogging is within the usable range until the next cleaning, cleaning or maintenance. It is useful for accurately predicting that the possibility is sufficient.

Next, as an application example, a method will be described in which the degree of clogging is the same, the differential pressure is calculated, and the cleaning timing is determined based on this differential pressure. As described above, FIG. 10 shows the difference in pressure difference with respect to the cumulative flow rate when a fluid having a constant concentration of clogging particles, here oil used as diesel engine oil, is caused to flow at a constant flow rate through a strainer having a rectangular cross section passage It shows the change and shows the differential pressure when the absolute viscosity of the fluid is changed to three levels.

The horizontal axis is a variable representing the degree of clogging, that is, a value having a linear relationship with the number of clogging particles. Therefore, the cleaning time is when the degree of clogging reaches a certain level, and the time when the horizontal axis reaches a certain point (A) is the cleaning time. The differential pressure at this point is 3 levels (B), (C) because the absolute viscosity of the fluid increases to 3 levels.
And (D), and changed. The values of the three levels of differential pressure become the values indicating the cleaning timing, and the cleaning timing (A) can be indicated without being affected by the change in the absolute viscosity of the fluid.

Here, a comparative example (conventional example) with respect to the method of determining the cleaning time will be described. In the conventional method, since the differential pressure is merely when the differential pressure reaches, for example, 70 kPa (E), the cleaning timing becomes (F), (G), and (H) due to the increase change of the absolute viscosity of the fluid. Will increase and change. For example, even if the chance of (G) happens to be a degree of clogging with relatively few problems, (F)
There is little clogging during the time of, and premature waste occurs,
Further, at the time of (H), the clogging progresses to a high degree, the rising speed of the differential pressure is high, and if the cleaning is delayed for a while, the particles passing through the strainer have large particles exceeding the planned size. If it is included, there is a risk that the bearing may be damaged or that the strainer-related device may be deformed or damaged.

In this respect, according to the method of determining the cleaning time described above, useless cleaning can be avoided and an appropriate cleaning time can be determined. Next, an embodiment of the clogging determination method for the strainer according to the invention of claim 3 will be described. The determination of the invention according to claim 3 is based on the differential pressure between the inlet and outlet of a strainer having a passage having a rectangular cross section and the absolute viscosity of the processing fluid, and the acceptable clogging area and the unacceptable area. A storage means in which possible clogging areas are assigned in advance is provided, and which of the two areas is determined based on the actual differential pressure and the absolute viscosity by referring to the storage means. is there.

It should be noted that, in the present embodiment, the writing means is used as a memory means in which the area of the acceptable clogging and the area of the unacceptable clogging are pre-assigned based on the differential pressure and the absolute viscosity of the processing fluid. A graph, which is an example of the created object, is provided, and the area is determined with reference to this graph. 12
Shows a graph of the differential pressure with respect to the absolute viscosity of the filtered fluid when the flow rate of the filtered fluid is a planned value.

This graph is divided into three regions by two lines 37 and 39. Lines 37 and 39 are loci of acceptable minimum and maximum differential pressure differentials, respectively, over the absolute viscosity range of the filtered fluid. Area 31 below line 37
Corresponds to a variable indicating an unacceptably low degree of clogging. The area 32 between the lines 37 and 39 corresponds to the variable indicating the acceptable strainer clogging degree, and the area 33 above the line 39 indicates an unacceptably high strainer clogging degree. Corresponds to the variable.

In general, if the variable indicating the degree of clogging of the strainer is unacceptably low, damage to the strainer, for example, damage such as a large leak hole that significantly reduces the resistance, will occur. If the variable indicating the degree of clogging of the strainer is unacceptably high,
Indicates that the differential pressure gauge or absolute viscosity measurement system is damaged, or that the strainer is operating outside normal limits.

In using such a graph, the strainer user reads the differential pressure and absolute viscosity of the strainer from the instrument when the flow rate of the filtered fluid is the planned value, and sees the graph of FIG. And the location on the graph corresponding to the absolute viscosity value. When the point corresponding to the value of the differential pressure and the value of the absolute viscosity is in the region 31 or 33, the continuation of the operation is stopped. This is because either the strainer or the instrument has failed.

When the points corresponding to the values of the differential pressure and the absolute viscosity are in the region 32, the strainer user knows that the degree of clogging of the strainer is sufficiently small and continues to use the strainer. . A third line 38 may be drawn between lines 37 and 39 to divide region 32 into two parts 32a and 32b. In this case, when the point corresponding to the value of the differential pressure and the value of the absolute viscosity is in the upper portion 32b of the region 32, the strainer user continues to operate, but an appropriate procedure such as backwashing, removal cleaning or repair is performed. I will report later that it is better to do it, and take action at the next processing. The graph of FIG. 12 is accurate only for one specific filtered fluid flow rate, and in practice, the graph has a plurality of combinations of the filtered fluid flow rate and different values of the dimensions of each strainer. Has been used. Alternatively, a conversion table is provided for use when a single graph scale is combined with many different flow rates and different values for each dimension of the strainer.

In general, fluctuations in the flow rate of the filtered fluid during operation are relatively small and can often be ignored. Further, in the graph of FIG. 12, the fourth line 40 is indicated by a high value of the differential pressure, for example, 90 to 300 kPa (preferably 10).
The portion 33b, the portion 32bb, and the portion 32ab may be provided on the line 40 by pulling to the position of 0 to 150 kPa). In this case, the points corresponding to the values of the differential pressure and the absolute viscosity are the portions 33b, 32bb and 32a on the line 40.
If it is in b, the continuation of the operation is stopped.
This is because it may reduce the particle removal performance of the strainer or cause deformation or breakage of the strainer element.

According to one embodiment of the invention described in claim 3, the strainer reads the differential pressure and the absolute viscosity from the instrument when the flow rate of the filtered fluid is the planned value, and the graph is seen.
The clogging of the strainer can be determined simply by determining the location on the graph that corresponds to these differential pressure and absolute viscosity values, and the clogging can be determined very easily and efficiently. The clogging state of can be accurately known, and cleaning, cleaning, or maintenance can be accurately performed.

In the embodiment of the judging method of the invention described in claim 3 described above, as the clogging judging method,
Based on the differential pressure and the absolute viscosity of the fluid to be processed in the strainer, a graph is provided as a written object in which the areas of the acceptable clogging and the unacceptable clogging are pre-assigned, Although the method of determining which of the two areas is based on the actual differential pressure and the absolute viscosity with reference to this graph has been described, the method is not limited to this.

That is, based on the differential pressure and the absolute viscosity of the fluid to be treated in the strainer, an electric field in which an acceptable clogging area and an unacceptable clogging area are pre-allocated,
A magnetic or optical storage means may be provided, and which storage area may be determined based on the actual differential pressure and the absolute viscosity by referring to this storage means.

[0080]

As described above, according to the first aspect of the present invention, the mechanical condition of the strainer having the passage having the rectangular cross-section is calculated from the calculated variable indicating the degree of clogging. It is possible to accurately know whether it is possible to properly perform cleaning, cleaning or maintenance, and accurately predict that there is sufficient possibility that it will be in the usable area until the next cleaning, cleaning or maintenance. Useful for.

As one of the variables, it is desirable to calculate the number of clogged particles, the gap between clogged particles, and the long side length of a passage having a rectangular cross section which is considered to be shortened due to clogging. It is preferred to use the calculated variable or the absolute value of the calculated variable. In the invention of claim 2, the numerical value (variable) of the degree of clogging of the strainer is
It becomes easy to calculate in the usage state where the strainer is installed in the flow path.

According to the third aspect of the present invention, only by determining the regions corresponding to the values of the actual differential pressure and the absolute viscosity,
It is possible to judge the clogging of the strainer, it is possible to judge the clogging very easily and conveniently, the clogging state of the strainer can be accurately known, and cleaning, cleaning or maintenance can be performed accurately. be able to. It is preferable that the storage means in the invention according to claim 3 is configured so that a plurality of combinations of the filtered fluid flow rate and the different values of the respective dimensions of the strainer are used.

[Brief description of drawings]

FIG. 1 is a view showing a group of cylinders, (A) is a perspective view, and (B) is a perspective view.
Is a plan view

FIG. 2 is a graph showing an estimated value and an actually measured value of a differential pressure due to a change in absolute viscosity.

FIG. 3 is a graph showing changes in differential pressure with respect to the number of circulations.

FIG. 4 is a graph showing the relationship between the number of particles corresponding to the measured differential pressure and the cumulative value of the mass of input particles.

FIG. 5 is a graph showing the relationship between the number of particles corresponding to the measured differential pressure and the number of circulations.

FIG. 6 is a graph showing the relationship between the measured differential pressure and the estimated differential pressure.

FIG. 7 is a graph showing measurement results of changes in differential pressure over time.

FIG. 8 is a graph showing the relationship between oil passage time and the number of clogging particles.

FIG. 9 is a graph showing the relationship between the measured differential pressure and the estimated differential pressure.

FIG. 10 is a graph for explaining a method of determining a cleaning time based on a differential pressure.

FIG. 11 is a configuration diagram of an embodiment of a clogging degree estimation device for a strainer.

[Fig. 12] Graph for explaining a clogging determination method for a strainer

FIG. 13 is a diagram showing a typical shape and dimensions of the oil passage of the strainer.

[Explanation of symbols]

 1 Strainer 7 Processor 5 Flowmeter 4 Absolute viscosity sensor 6 Differential pressure gauge 8-10, 18 Notification device 11 Keyboard 12 Storage device 21 Instrument panel 22-25 Notification device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noboru Isobe 8-8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Nippon Oil Oil Co., Ltd. Central Technology Research Institute

Claims (3)

[Claims] 1. A strainer having a square cross-section fluid passage, the pressure difference between the inlet and outlet of the strainer, the absolute viscosity of the fluid to be treated by the strainer, the dimensions of each portion of the strainer, and the flow rate of the filtered fluid. A method for estimating the degree of clogging of a strainer, which comprises estimating a degree of clogging by calculating a variable that represents the degree of clogging of the vessel. 2. A means for outputting differential pressure information between an inlet and an outlet of a strainer having a fluid passage having a rectangular cross-section, a means for outputting absolute viscosity information of a fluid to be processed by the strainer, and a strainer. Means for outputting the dimension information of each part of the container, means for outputting the flow rate information of the filtered fluid, and means for calculating a variable indicating the degree of clogging of the strainer based on each signal output from the output means. An apparatus for estimating the degree of clogging of a strainer, comprising: 3. An acceptable clogging area based on the differential pressure between the inlet and outlet of a strainer having a fluid passage having a rectangular cross-section and the absolute viscosity of the fluid treated in the strainer. A storage means in which an unacceptable clogging area is assigned in advance is provided, and which of the two areas is determined based on the actual differential pressure and absolute viscosity by referring to the storage means. A method for determining clogging of a strainer characterized by the fact that: