JPH045554A - Particulate guide-in device - Google Patents

Abstract

PURPOSE:To supply only desired particulates to the detector of a element analyzer which utilizes microwave-induced plasma by sucking solid particles and supplying them to a plasma generation part by an aspirator. CONSTITUTION:After the air at the gas substitution part 5 in a case 8 is sicked and discarded for sufficient substitution with carrier gas, an arm 4 is put close to a constant distance to the surface of a filter 3 and the carrier gas is supplied to the aspirator 1 at a small flow rate of about 300ml per minute to suck particulates sticking on the surface of the filter 3 together with atmospheric gas. Then a motor 9 is driven to move the arm 4 in a circumferential direction at a constant speed and the surface of the filter 3 is scanned by the aspirator 1 to suck the particulates sticking on the surface of the filter 3, one after another, from the suction opening of the aspirator 1. Consequently, plasma gas is used as the carrier gas to supply desired particulates to the detector.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a particle introduction device that supplies desired particles to a detector of an elemental analyzer using microwave induced plasma.

<Conventional technology> Conventionally known particulate introduction devices use a pump or ejector as a suction device to suck in desired particulates from a sampling space such as the atmosphere, and introduce them into an optical particulate measuring device using a laser (light). It was configured to do so.

However, since elemental analyzers using microwave induced plasma require a carrier gas, it is difficult to introduce air directly; even a small amount of contamination has a negative effect on the microwave induced plasma, and the amount of fine particles that can be introduced is It also had the disadvantage that it was limited to very small quantities.

<Problems to be Solved by the Invention> The present invention has been made in view of the drawbacks of the conventional examples, and its purpose is to use plasma gas flowing at a small flow rate of about 300 m1/min as a carrier gas to collect desired fine particles. The object of the present invention is to provide a particulate introduction device that can supply only the above particles to a detector of an elemental analyzer using microwave-induced plasma.

Means for Solving the Problems> The feature of the present invention that solves the above problems is that in a particulate introduction device, an aspirator, a filter having solid particulates attached to its surface, and a filter for fixing the filter are provided. an arm on which the unit is attached; a fixed shaft that converts rotation of a first motor into horizontal rotational movement of the arm; and a ball screw that converts rotation of a second motor into vertical linear movement of the arm; When the suction port of the aspirator is close to the filter at a certain distance,
When carrier gas flowing at a small flow rate of 0.00 m1 is supplied to the aspirator, the solid particles are sucked by the aspirator and supplied to the plasma generating section.

<Example> Hereinafter, the present invention will be described in detail using the drawings. 1st
The figure is an explanatory view of the configuration of an embodiment of the present invention, and in the figure, 1 is an aspirator, 2 is a filter unit for fixing the filter 3, 4 is an arm, 5 is a gas replacement part, and 6 is a backlash of, for example, 0.01 mm or less. The ball screw 7゜7- is designed to cancel the backlash and transfer the movement (rotational movement) from the second motor (described later) to the two-axis movement (up and down) of the filter 3 via the ball screw 6. 8 is a case configured to prevent air from leaking in from the outside with a screw and an O-ring seal; 9 is a first motor consisting of a stepping motor with extremely high angular resolution; 10 is a timing belt that transmits the rotation of the first motor 9. Furthermore, when Ar gas is used as the carrier gas, the suction ratio between the carrier gas and the sample gas is, for example, 1:3, and when He gas is used as the carrier gas, the suction ratio between the carrier gas and the sample gas is 1:3. For example, 1:1.5,
The suction characteristics of the aspirator 1 are designed. Furthermore, the distance between the suction port of the aspirator 1 and the filter 3 is 0.01 mm.
It is controlled to be as follows.

In the embodiment of the present invention having the configuration as shown in FIG.
First, the lid of the case 8 is opened, and the filter unit 2 is fixed with the filter 3 having solid particles attached to its surface.
After attaching it to the arm 4, close the lid of the case 8. After that, the second motor (not shown) is driven to lower the arm 4 to the bottom of the ball screw 8, and then the first motor 9 is rotated to rotate the arm 4 horizontally by 90'' and move it to the position of the aspirator 1. Furthermore, the inside of the case 8 is a gas replacement section 5, in which the air inside is sucked and discarded by the suction bong 1 (suction pump 14 in FIG. 2) and replaced with carrier gas. After sufficient replacement, when the second motor is driven again, the arm 4 moves up the ball screw 6 and stops when it approaches the surface of the filter 3 at a certain distance. Gas is supplied, and the particles adhering to the surface of the filter 3 are sucked together with the atmospheric gas.Then, the first motor 9 is driven to move the arm 4 at a constant speed in the circumferential direction perpendicular to the plane of the paper in Figure 1. As the aspirator 1 scans the surface of the filter 3, fine particles adhering to the surface of the filter 3 are suctioned one after another from the suction port of the aspirator 1.

On the other hand, FIG. 2 is a detailed explanatory diagram of the present invention, and in the figure, l
1 is a carrier gas inlet, 12b is a replacement gas inlet, 12c is a gas outlet, 13a to 13e are on-off valves, 14 is a suction pump, 15 is a discharge tube, 16 is a cavity, and 17 is a glazma.

In the usage example of the embodiment of the present invention having the configuration as shown in FIG. 2, carrier scum (for example, Ar or He) is supplied to the carrier scum inlet 12a from a cylinder (not shown), and the on-off valve 13a and aspirator 1 are Through the discharge tube 15
be introduced within. Further, in the center of the cavity 9, a microwave generator (not shown) generates a microwave (100 to 15
0W microwave power) is irradiated, and cavity 1
The carrier gas in the discharge tube 15 inserted into the center of the discharge tube 6 is excited to generate plasma 17.

Further, the fine particles adhering to the surface of the filter 3 are sucked by the aspirator 1 as described above and sent together with the carrier gas to the plasma 17 in the discharge tube 15, where they are dissociated by the plasma and emit light. The light generated in the discharge tube 15 in this way is detected by a monochromator (not shown), and then subjected to signal processing by a signal processor (not shown) to detect fine particles or component elements in the fine particles. be analyzed.

It should be noted that the present invention is not limited to the above-described embodiments, and can be modified in various ways, for example, as shown in the following (1) to (2). ■Mount a plurality of filter units 2 shown in Fig. 1 on the turntable. ■Filter unit 2 in Figure 1
Instead, a roll-type strip filter is used for continuous measurement. (2) A sampler consisting of a filter unit, a suction pump, a flow meter, and a timer can be configured quantitatively with the disperser according to the present invention without providing a separate sampler.

<Effects of the Invention> As explained in detail above, the present invention provides a particulate introduction device that stably supplies a sample to the plasma generation section of a microwave-induced plasma elemental analyzer. an arm equipped with a filter unit that fixes the filter;
A fixed shaft that converts the rotation of the first motor into horizontal rotational movement of the arm and a ball screw that converts the rotation of the second motor into vertical linear movement of the arm are provided, and the suction port of the aspirator is connected to the filter. When the carrier gas flowing at a small flow rate of about 300 ml per minute is supplied to the aspirator while being close to a certain distance, the solid particles are sucked by the aspirator and supplied to the plasma generating section. .

Therefore, a particle introduction device is realized that can supply desired particles to a detector of an elemental analyzer using microwave induced plasma using plasma gas as a carrier gas. That is, (1) Since it is dissociated in pure Ar or He plasma, H2O, 02N2. It is possible to measure fine particles with high sensitivity regardless of whether they are metal elements or non-metal elements without being influenced by a matrix such as Co2.

■The amount of sample can be changed according to the particle concentration (so-called cleanliness) in the sampling space, so a constant amount of particles can always be sampled.

■By changing the moving speed of the aspirator and the gap between the aspirator's suction port and the filter, it is possible to control both time and quantity.

■In the conventional example, only the diameter and number of fine particles could be known, but according to the present invention, the elements constituting the fine particles can be determined by accessing the spectrometer (optical system in Figure 1). Be able to identify.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of an example of use of the embodiment of the present invention. 1... Aspirator, 2... Filter unit, 3
...Filter, 4...Arm, 5...Gas replacement unit, 6...Ball screw, 7.7-...Fixed shaft, 8...
- Case, 9... Motor 11... Disperser 112a... Carrier gas inlet, 12b... Replacement gas inlet, 12c... Waste discharge port, 13a to 13e... Open/close valve, 14 ...Suction pump, 15...Discharge tube, 16...Cavity, 17...
plasma

Claims (1)

[Claims] In a particle introduction device that stably supplies a sample to the plasma generation part of an elemental analyzer using microwave induced plasma,
an aspirator, a filter having solid particles attached to its surface, an arm to which a filter unit for fixing the filter is attached, a fixed shaft for converting rotation of a first motor into horizontal rotational movement of the arm; and a ball screw that converts the rotation of the two motors into vertical linear movement of the arm, and the carrier flows at a small flow rate of about 300 ml per minute when the suction port of the aspirator is close to the filter at a certain distance. A particle introduction device characterized in that when gas is supplied to the aspirator, the solid particles are sucked by the aspirator and supplied to the plasma generation section.