JPS60262040A - Apparatus for detecting quantity of fine particles - Google Patents

Abstract

PURPOSE:To detect fine particles in a fluid with high sensitivity and high accuracy, by connecting a filter and a throttle part to one of branched pipelines while connecting a throttle part and a filter to the other branched pipeline in the reverse order and providing a differential pressure detector for detecting the pressure difference between both pipelines. CONSTITUTION:A first filter 2 for collecting fine particles in a fluid is connected to the outlet opening 1b of one of branched pipelines 1 and a first throttle part 4 for generating pressure drop in the fluid is connected thereto through a pipeline 3. A second throttle part 5 is connected to the outlet opening 1c of the other branched pipeline and a second filter 7 is connected thereto through a pipeline 6. Further, between the first pipeline 3 and the second pipeline 6, a differential pressure detector 8 for detecting the pressure difference between the pipelines 3, 6 is connected through pressure take-out pipes 9, 10 to form a bridge circuit. By this simple constitution, the quantity of fine particles in the fluid can be continuously detected within a short time with high sensitivity and high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a particulate amount detection device that detects the amount of particulates contained in a fluid.

Generally, the hydraulic fluid in a hydraulic device is kept clean at the beginning of operation, but as time passes, it gradually becomes contaminated with wear powder generated from the hydraulic pump, motor, etc. inside the device, and foreign matter entering from the outside. This causes a large amount of fine particles, which are contaminants, to be suspended in the hydraulic fluid. Fine particles in this hydraulic oil can accelerate wear on the sliding parts of hydraulic pumps, motors, valves, etc., shortening the life of these devices, or can stick to moving parts and cause equipment failure, so filters, etc. It is necessary to maintain the cleanliness of the hydraulic oil by using a cleaning device to purify and regenerate the hydraulic oil, replace the hydraulic oil, etc. In order to effectively maintain the cleanliness of this hydraulic oil, it is important to accurately understand the state of contamination of the hydraulic oil within the device.

Conventionally, as a method for ascertaining the contamination state of hydraulic oil in equipment, for example, light is incident into the fluid to be detected, and this light is scattered and attenuated by fine particles in the fluid, and the amount of fine particles is detected from the amount of light attenuation. There is a method in which the fluid to be detected is passed through a filter, and the amount of particulates is detected from the pressure drop of the fluid that occurs when the particulates are caught by the filter. However, although these methods have the advantage of being able to continuously detect on-line, the former has the disadvantage that the equipment is complicated, and the latter has the disadvantage of low detection sensitivity. In addition to the above methods, there are also methods in which particles in the fluid are captured with a filter and weighed with a scale, or a small amount of sample is extracted from the fluid to be detected, filtered, and then weighed with a microscope or subjected to spectroscopic analysis. There are also methods of measuring the amount of water using a sensor, but these methods have the disadvantage that it takes time to obtain detection results.

The present invention was made based on the above circumstances, and its purpose is to provide a method for detecting the amount of particulates in a fluid with high sensitivity and accuracy using a simple configuration, and continuously in a short period of time. The object of the present invention is to provide a detection device.

In order to achieve the above object, the present invention provides a branch pipe line having an inlet opening that serves as an inlet for a fluid to be detected, and an outlet opening from which the fluid flowing in from the inlet opening flows out in three directions; a first filter that is connected to one outlet opening and captures particulates in the fluid flowing out from the branch pipe; a first restrictor that causes a pressure drop in the fluid that has passed through the first filter; a first conduit connecting the first constriction and the first filter; a second constriction connected to the other outlet opening of the branch pipe and causing a pressure drop in the fluid flowing out from the branch conduit; a second filter that captures particulates in the fluid that has passed through the second constriction section; a second conduit that connects the second filter and the second constriction section; It is equipped with a differential pressure detector for detecting a pressure difference with the first pipe line, and means for detecting the amount of particulates in the fluid based on the pressure difference measured by the differential pressure detector. . 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The figure is a schematic configuration diagram of a particulate amount detection device showing an embodiment of the present invention.
This is a branch pipe line having three outlet openings 1b and 1c through which the fluid flowing in through the inlet opening 1a flows out in three directions.

A first filter 2 is provided at one outlet opening 1b of the branch pipe 1 to capture particulates in the fluid flowing out from the branch pipe 1.
is connected. A first constriction section 4 is connected to the first filter 2 via a first conduit 3, and is configured to cause the fluid that has passed through the filter 2 to generate a pressure drop. Further, a second constriction portion 5 is connected to the other outlet opening 1C of the branch pipe 1 to cause a pressure drop in the fluid flowing out from the branch pipe 1. A second filter 7 is connected to the second constriction section 5 via a second conduit 6, and is configured to capture particulates in the fluid that has passed through the constriction section 5. A differential pressure detector 8 for detecting the pressure difference between these pipes 3 and 6 is connected between the first pipe line 3 and the second pipe line 6 via pressure extraction pipes 9 and 10. and form a bridge circuit.

The first and second filters 2 and 7 have, for example, a filtration element formed of a porous material or a fibrous material such as metal or organic material in the housing, and this filtration element traps fine particles in the fluid. It is composed of Further, the first and second constricting portions 4.5 are made of, for example, chalk or a sharpener, and the opening areas of these constricting portions 4, 5 are larger upwardly than the size of the fine particles in the fluid.
Particulates are trapped in the opening to prevent pressure drop from changing. That is, the respective pressure drops of the filter 2.7 and the restrictor 4.5 are set so that the bridge circuit is in an equilibrium state only when a clean fluid to be detected that does not contain particulates flows through it. Further, the differential pressure detector 8 uses a normal differential pressure detection mechanism using, for example, a spool valve, diaphragm, Bourdon tube, Vinton, etc., and is configured to convert the detected differential pressure into an electrical signal and output it. has been done.

In the figure, reference numeral 11 denotes a return pipe through which the fluids flowing out from the first throttle section 4 and the second orifice 7 are combined and flowed out, and serves as an outlet for the fluid to be detected.

Next, the operation of this embodiment configured as described above will be explained.

First, the initial pressure drop of filters 2 and 7 (filtering
(Py B e P y l) (Py B e P y l) (Py B e P y l) The conditions for achieving an equilibrium state are PPa"" PRb...・(1) P, b-P□ ...(2) It becomes. When the above equations (1) and (2) are expressed using fluid flow resistance, the results are as follows.

Here, Zya a Zpb indicates the initial flow resistance of the filter 2.7, Zia * Zib is the flow resistance of the constriction part 4.5, and Q, , Qb are the flow rates of the fluid flowing on the pipe line 3.6 side, respectively. .

The water is divided and flows out from the return pipe 11 through two flow paths: a flow path consisting of the filter 2 and the constriction section 4 and a flow path consisting of the constriction section 5 and the filter 7. At this time, the flow resistance of the test is Zra
The equilibrium condition of w Zyb -7aa -7Rb is satisfied, and the bridge circuit is in an equilibrium state. At this time, no pressure difference occurs in the pipe line 3.6111, and Qa / Q b
"1, so the differential pressure detector 8 does not output a differential pressure signal.

On the other hand, if the fluid to be detected contains particulates, the particulates are captured by the filter 2.7 and an enrichment prevention effect occurs.
The pressure drop across filters 2, 7 increases. On the other hand, since the pressure drop in the constriction section 4.5 remains unchanged even when it contains fine particles, the fluid pressure in the conduit 3 is lower than in the equilibrium state, and the conduit I8 detects and responds to the pressure difference. Outputs a differential pressure signal. By displaying the analog value of the differential pressure signal output from the differential pressure detector 8 using, for example, a meter, it is possible to detect the proportion of particulates contained in the fluid.

In this way, according to the present embodiment, a bridge circuit is formed using two filters 2.7, two throttle sections 4.5, and one differential pressure detector 8, and the fluid flowing through the bridge circuit is When the fluid is clean, it is in an equilibrium state, and when there are particles in the fluid, the equilibrium state is disrupted.By detecting this with the differential pressure detector 8, the amount of particles in the fluid can be determined by sensitivity and It can be detected with high precision and continuously in a short time. Note that in the above embodiment, the first aperture section 4 and the second filter 7
The outlet of the
Although the fluids flowing out from the filter 7 and the filter 7 are made to join together, according to the present invention, the same effect can be obtained even if the return pipe is made into two pipes without making them join. Further, according to the present invention, a variable throttle mechanism may be added to either or both of the throttle section 4.5 and/or the filter 2.7, which can manually adjust the pressure drop. In this way, the aperture part 4.5
Since the error in the pressure drop of the filter 2.7 can be absorbed, the equilibrium state can be easily adjusted.

As is clear from the above description, according to the present invention, there is provided a branch pipe having an inlet opening that serves as an inlet for a fluid to be detected, and an outlet opening through which the fluid flowing in from the inlet opening flows out in three directions; a first filter that is connected to one outlet opening of the channel and captures particulates in the fluid flowing out from the branch pipe; and a first constriction that causes a pressure drop in the fluid that has passed through the first filter; A first conduit that connects these first constrictions and the first filter, and a second constriction that is connected to the other outlet opening of the branch pipe and causes a pressure drop in the fluid flowing out from the branch conduit. a second filter that captures particulates in the fluid that has passed through the second constriction section; a second pipe line that connects these second filters and the second constriction section; A differential pressure detector for detecting a pressure difference between the fluid passage and the first pipeline, and a means for detecting the amount of particulates in the fluid based on the pressure difference measured by the differential pressure detector. Therefore, it is possible to provide a particulate amount detection device that can continuously detect the amount of particulates in a fluid in a short time with high sensitivity and precision using a simple configuration.

[Brief explanation of the drawing]

The figure is a schematic configuration diagram of a particulate amount detection device showing an embodiment of the present invention. 1... Branch pipe, 2.7... Filter, 4, 5...
Throttle section, 8... Differential pressure detector. Applicant Sub-Attorney Patent Attorney Takehiko Suzue Procedural Amendment Showa 1999.12. Mr. Manabu Shiga, Commissioner of the Japan Patent Office 1. Indication of the case Japanese Patent Application No. 59-117776 2. Name of the invention Particulate amount detection device 3. Person making the amendment Relationship with the case Patent applicant (620) Mitsubishi Heavy Industries Co., Ltd. 4, sub-agent ゛17 Mori Building 7, 1-26-5 Toranomon, Minato-ku, Tokyo.
Contents of the amendment: (1) The following sentence will be added next to "is." on page 7, line 12 of the specification. (2) On page 7, line 16 of the specification. The above is a general formula for the equilibrium condition of this bridge circuit. Here, if Zp・a = 'Zpb = ZRa = ZRb, that is, filters 2 and 7 are the same, and filter 4 is
and 5 are the same, and if the flow resistances of these filters and the restrictor are made equal, this satisfies the above equilibrium condition. (3) "Equilibrium condition" on page 7, line 17 of the specification is corrected to "bridge circuit." (4) Delete "[each filter...]" from lines 4 to 6 on page 8 of the specification. (5) “Because the pressure difference is...” on page 8 of the specification, lines 7-8
Correct it to ``Because there is no pressure difference.'' (6) On page 8 of the specification, lines 17 and 18, [equilibrium state ~ occurs, j is corrected to read "equilibrium state collapses."

Claims (1)

[Claims] A branch pipe line having an inlet opening that serves as an inlet for a fluid to be detected, and an outlet opening that divides the fluid flowing in from the inlet opening into two and flows out, and a branch pipe line 1 that is connected to the outlet opening of one of the branch pipes. a first filter that captures particulates in the fluid that has flowed out; a first constriction that causes a pressure drop in the fluid that has passed through the first filter; a first pipe line to be connected, a second constriction part connected to the other outlet opening of the branch pipe and causing a pressure drop in the fluid flowing out from the branch pipe; and a fluid passing through the second constriction part. a second filter that captures particulates in the fluid; a second pipe line that connects the second filter and the second constriction section; and a second pipe line that connects the second pipe line and the first pipe line. A particulate amount detection device comprising: a differential pressure detector for detecting a pressure difference; and means for detecting the amount of particulates in the fluid based on the pressure difference measured by the differential pressure detector.