JP2005351782A - Detector and method for detecting particle in liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-liquid particle detector capable of eliminating incompleteness in discrimination between an in-liquid particle and a bubble in a conventional in-liquid particle detector to measure only the in-liquid particle, by simple constitution. <P>SOLUTION: In this in-liquid particle detector of the present invention, a sample liquid containing the particle of a measuring object and the bubble is made to flow in a particle-bubble separation means 3 arranged in an upstream of a detection cell 2 in a flow passage 1 and is irradiated with a detecting light from a particle detecting means 4 arranged in a downstream of the detection cell 2, the particle 13 in a liquid is detected by a light scattering method, and an output signal of the detected particle is transmitted to a signal processing means 5 to measure a particle size and to count the particle number. Electrodes are provided respectively between a flow-in port side and a flow-out port side of the particle-bubble separation means 3, and Lorentz force due to an electric field impressed between the electrodes and a magnetic field impressed perpendicularly thereto is imparted to the particle 13 to be separated from an orbit 11 of the bubble. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-liquid particle detection apparatus and a detection method for detecting a particle size and the number of particles by separating particles and bubbles in a liquid in which particles and bubbles are mixed.

  Conventional particle detectors that separate particles and bubbles in the liquid and detect the particle size and number of particles are changed by changing the pressure in the liquid using a method that uses temperature changes. Some used the difference in light intensity between before and after.

  For example, in Patent Document 1, light is irradiated to a measurement cell in a state in which the sample liquid is circulated in the measurement cell, and scattered light generated from fine particles contained in the sample liquid is detected by a photodetector, and the output thereof In-liquid particle measurement system for counting the number of particles on the basis of the above, a cooling device for cooling the sample liquid and dissolving bubbles mixed in the sample liquid upstream of the measurement cell, and the sample liquid A defoaming device for separating and removing bubbles mixed in from the sample solution is provided in series with each other, and a bubble discharge port provided at an upper portion of the defoaming device is connected to the downstream side of the measurement cell. Thus, a configuration is disclosed in which only particles can be detected.

  Patent Document 2 discloses first and second light scattering particle detectors that output signals corresponding to particle diameters such as particles and bubbles present in a sample liquid passing through a flow path, Comparing the output signals of the cooler, which is installed in the flow path between the second light scattering particle detectors, and cools the sample liquid passing therethrough to a predetermined temperature, and the first and second light scattering particle detectors A configuration is disclosed in which only a particle can be detected by providing a signal processing unit that processes and calculates the particle size and number of particles such as particles and bubbles.

In Patent Document 3, a detection cell formed of a sealed container that stores a sample liquid to be measured, and a pressure applying unit that applies a predetermined pressure to the measurement target liquid stored in the detection cell pressurize, The pressure control unit that controls the pressure applied by the pressure applying unit to change is changed, the optical detection unit irradiates light to the liquid stored in the storage unit, and the detection light is output as a detection signal. Based on detection signals detected before and after the pressure state, the calculation processing unit calculates detection data for only fine particles excluding bubbles contained in the liquid, thereby detecting only fine particles excluding bubbles contained in the liquid. A configuration for extracting data and selecting particles and bubbles is disclosed.
JP-A-11-316185 JP-A-10-104150 JP 2000-105186 A

  However, in the liquid particle detection device disclosed in Patent Document 1, bubbles may not be completely removed. In the configuration disclosed in Patent Document 2, two or more detectors are required and the first detection is performed. It was difficult to discriminate between particles and bubbles unless it was guaranteed that the particles detected by the vessel were the same particles as detected by the second and subsequent detectors. Furthermore, in the method of selecting bubbles by changing the pressure disclosed in Patent Document 3, it is necessary to seal the bubbles in order to change the pressure, and it is difficult to discriminate particles and bubbles in the liquid in-line. Therefore, it is difficult to detect the number of sample liquid particles in which particles and bubbles are mixed.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to detect an in-liquid particle detector and a detector for counting the number of particles by distinguishing between particles in a sample liquid and bubbles. A method is provided.

  In order to solve the above-described problems, the in-liquid particle detection device of the present invention exists in a detection cell provided in a flow channel and a sample liquid passing through a flow channel disposed on the upstream side of the detection cell. Particle / bubble separating means for separating particles and bubbles, and particle detecting means for outputting a signal corresponding to the particle diameter of particles and bubbles present in the sample liquid disposed on the downstream side of the detection cell; It is characterized by comprising signal processing means for calculating the particle size and the number of particles such as particles and bubbles by computing the output signal of the particle detecting means.

  The particle / bubble separating means preferably includes electrodes at the inlet and outlet of the sample liquid, respectively, and magnetic field generating means for applying a magnetic field in a direction perpendicular to the electrolysis generated between the electrodes. .

  In the middle of the flow path, a separation wall is provided in a direction parallel to the flow of the sample liquid, and the particle detection means is disposed on one side of the flow path separated by the separation wall. Is preferred.

  The liquid particle detection method of the present invention includes a step of flowing a sample liquid to be measured in a detection cell provided in a flow channel, and a flow channel disposed upstream of the detection cell. Separating the particles from the bubbles by applying an electric field in a direction parallel to the magnetic field and applying a magnetic field in a direction perpendicular to the electric field to change the trajectory between the particles and the bubbles contained in the sample liquid. And.

  The submerged particle detection apparatus and method of the present invention have the above-described configuration, and can separate the particles in the liquid flowing through the flow path from the bubbles, and can accurately measure the number of particles in the liquid. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a submerged particle detection apparatus according to an embodiment of the present invention, and FIG. 2 is a principle explanatory diagram of a particle detection method using the submerged particle detection apparatus according to the embodiment of the present invention.

  In FIG. 1, a sample liquid containing particles and bubbles to be detected is passed through particle bubble separation means 3 disposed upstream of the detection cell 2 in the flow path 1. Electrodes are respectively provided between the inlet side and the outlet side of the particle bubble separation means 3, and these electrodes are connected to a power source (not shown). Detection light is irradiated from particle detection means 4 arranged on the downstream side of the detection cell 2, and particles in the liquid are detected by a light scattering method. The output signal of the particle detected here is transmitted to the signal processing means 5 and counted as the particle size and the number of particles.

  Next, the principle of a method for separating particles and bubbles in the liquid particle detection apparatus will be described with reference to FIG.

  Assuming that the energy of the particles 13 in the sample liquid is E, the following equation is obtained.

E = q · e · V = 1/2 · m · v ² (Formula 1)
Here, q is the number of charges of the particles 13 in the sample liquid, e is the charge of electrons, V is the applied voltage between the electrodes, m is the mass of the particles 13, and v is the flow speed of the sample liquid.

  Further, since the magnetic field 6 is applied to the particle bubble separating means 3 so as to be orthogonal to the flow of the sample liquid, Lorentz force acts on the particles 13 in the sample liquid. The direction of the magnetic field 6 is a direction from the back to the front of the page, and the magnetic field can be generated by, for example, arranging a magnet with a flow path interposed therebetween. The Lorentz force is expressed by (Equation 2).

F1 = v · q · e · B (Formula 2)
Here, F1 is the Lorentz force, and the trajectory 8 of the particle that has received the Lorentz force F1 is shown in the figure. B is the strength of the magnetic field.

  Since the particles 13 that have received the Lorentz force take a circular motion with an orbital radius of 7, a centrifugal force acts. The centrifugal force is expressed by (Equation 3).

F2 = m · v ² / R (Formula 3)
Here, F2 is a centrifugal force, and the trajectory 9 of the particles subjected to the centrifugal force is shown in the figure. R is the orbital radius 7 of the particle 13.

  In the equilibrium state in the particle bubble separation means 3, the Lorentz force 8 and the centrifugal force 9 are balanced, that is, F1 = F2 holds. Such a relationship holds.

BR = k ((mE) / q) ^1/2 (Formula 4)
As can be seen from (Equation 4), the orbit radius 7 of the particle 13 in the particle bubble separating means 3 is a magnetic field if the flow velocity v of the sample liquid is constant, that is, the energy E of the particle 13 is constant. Since it is inversely proportional to the strength of 6, the particles 13 passing through the particle bubble separating means 3 pass through the trajectory 10 corresponding to the strength of the magnetic field 6.

  A separation wall 12 is provided on the downstream side of the magnetic field application unit. The particles 13 in the liquid can be separated by flowing on one side of the separation wall 12 and the bubbles 14 can be separated by flowing on the other side of the separation wall 12.

  After the particles 13 and the bubbles 14 in the liquid are separated, the particles 13 alone in the liquid are irradiated with the detection light from the particle detection means 4 disposed only on one side of the separation wall 12 on the downstream side of the detection cell 2. Is detected by a light scattering method. The output signal of the particle | grains 13 detected here is transmitted to the signal processing means 5, and is counted as a particle size and a particle number.

  After separating the particles 13 and the bubbles 14 in the liquid, the particle detection means 4 may be a method other than the light scattering method in order to calculate only the particles 13.

  The particle detecting means 4 is provided with a light source and a light detector, detects the scattered light generated from the particles 13 by transmitting the light emitted from the light source through the sample liquid containing the particles 13, and this scattered light. The diameter and number of the particles 13 may be obtained from the intensity value.

  Alternatively, the particle 13 moving with the Lorentz force 8 may be measured with a CCD camera, and the diameter and number of the particles 13 may be obtained.

  The submerged particle detection apparatus and method of the present invention are useful in that only particles can be measured by selecting particles and bubbles in the liquid in the submerged particle measurement field.

Configuration schematic diagram of liquid particle detection device in an embodiment of the present invention Explanatory drawing of the principle of the particle | grain detection method using the particle | grain detection apparatus in a liquid in embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flow path 2 Detection cell 3 Particle bubble separation means 4 Particle detection means 5 Signal processing means 6 Magnetic field 7 Particle orbit radius 8 Orbit of particle subjected to Lorentz force 9 Orbit of particle subjected to centrifugal force 10 Actual orbit of particle 11 Bubble Orbit 12 Separation Wall 13 Particle 14 Bubble

Claims (4)

A detection cell provided in the flow path;
Particle / bubble separating means for separating particles or bubbles present in the sample liquid passing through the flow path disposed on the upstream side of the detection cell;
Particle detection means for outputting a signal corresponding to the particle size of particles or bubbles present in the sample liquid disposed on the downstream side of the detection cell;
An in-liquid particle detection apparatus comprising signal processing means for calculating the particle size and the number of particles such as particles and bubbles by computing the output signal of the particle detection means. The particle / bubble separating means includes a magnetic field generating means for providing electrodes at the inlet and outlet of the sample liquid, respectively, and applying a magnetic field in a direction perpendicular to electrolysis generated between the electrodes. The in-liquid particle detector according to claim 1. In the middle of the flow path, a separation wall is provided in a direction parallel to the flow of the sample liquid, and the particle detection means is disposed on one side of the flow path separated by the separation wall. The in-liquid particle detection device according to claim 2. Flowing a sample liquid to be measured into a detection cell provided in the flow path;
Particles contained in the sample liquid by applying an electric field in a direction parallel to the flow path and applying a magnetic field in a direction perpendicular to the electric field in a flow path disposed upstream of the detection cell Separating the particles and the bubbles by changing the trajectory between the bubbles and the bubbles;
A liquid particle detection method comprising a step of counting the particle size and the number of particles of the separated particles.

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