JPS6319794Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an X-ray analyzer suitable for performing automatic fluorescence X-ray analysis on powder samples such as cement raw materials.

In the blending process of cement raw materials, it is necessary to analyze the components of each raw material and determine the blending ratio. A fluorescent X-ray analyzer is used for this analysis. FIG. 1 is a diagram showing an embodiment of an invented fluorescent X-ray analyzer (Utility Application No. 164587/1987) which has already been proposed by the applicant of the present invention. A powder sample 11 is continuously supplied from the hopper 4 to the upper part of a wheel-shaped conveyor 3 inside the container 1. It is rotated counterclockwise. A window 6 is provided on the top surface of the container 5, and before the sample 11 is brought under the window 6, it is sandwiched between the bottom surface of the shaping plate 5 and the conveyor 3, and is compacted to a certain density so that the top surface is It is molded into a smooth plane and has an X at the window 6 position.
Line irradiation is performed.

In an apparatus configured as described above, in order to obtain correct analysis results, it is desirable that the surface of the sample brought below the window be smooth and have a constant density. In this type of analyzer, a spectroscopic chamber located above the window 6 is filled with helium gas to prevent X-rays from attenuating. When the space of the spectroscopic chamber and the space of the container 1 are separated by beryllium foil or the like, and helium is poured into the space between the beryllium foil and the surface of the sample 11, the sample 1 supplied from the hopper 4
When the surface of 1 comes into contact with a helium atmosphere, the surface is gouged and its flatness deteriorates.

An object of the present invention is to provide an X-ray analysis apparatus that can prevent the flatness of the surface from decreasing.

In order to achieve the above object, the X-ray analyzer according to the present invention continuously supplies a powdered sample onto a rotating wheel, and presses the powdered sample onto the rotating wheel surface with a shoe installed at a fixed position opposite to the wheel surface. In an X-ray analyzer that forms a sample plane by irradiating the plane with X-rays and detects the generated fluorescent X-rays to analyze sample components, before the sample is pressed onto the shoe, A means is provided for supplying the same gas with a low X-ray absorption capacity as that filled at the X-ray irradiation position into the sample.

According to the above structure, the object of the present invention can be completely achieved.

The analysis device according to the present invention will be described in more detail below with reference to the drawings and the like. FIG. 2 is a schematic diagram showing the device according to the present invention, and FIG. 3 is a partially enlarged sectional view. Elements common to those of the conventional device shown in FIG. 1 are given the same reference numerals. In the figure, 8 indicates a spectroscopic chamber, and this spectroscopic chamber includes a goniometer 9,
10 are provided. The point that the sample is pressed against the flat surface of the wheel 3 via the hopper 4 and brought into the irradiation space Q (see FIG. 3) is the same as described in connection with FIG. 1. Space Q between the spectroscopic chamber 8 and the surface of the sample 11 irradiated with X-rays
are divided by beryllium foil windows. Helium gas is supplied to this space Q through a hole 5a passing through the shoe 5, and is discharged through a passage 6a formed between the lower surface of the other shoe 6 and the sample surface. The same gas atmosphere as in the spectroscopic chamber is formed. The purpose of the shoe 6 is to separate the space Q from the inside of the container 1 rather than to attach the sample to the wheel 3.

Before the sample supplied from the hopper 4 is shaped by the shoe 5, helium is supplied from the helium supply pipe 12, and the sample powder is shaped while containing helium.

Let's consider an experiment in which cement raw materials are the subject of analysis. The samples targeted for this study had a particle size of 60 mesh or less and a moisture content of 1% or less.

If the space Q is kept in a helium atmosphere without supplying helium gas from the helium supply pipe 12, the sample surface formed by the shoe will lift up when it reaches the space Q, causing cracks.

When helium gas was supplied from the helium supply pipe 12 and pressurized by the shoe 5, when the space Q was reached, no cracks were generated at all and a smooth plane could be maintained.

As explained above, if helium is sprayed in advance and shaped as in the present invention, a smooth plane is maintained in the space Q.

The reasons why a sample containing air floats up when it enters a helium atmosphere are as follows.

(b) Helium enters the air-containing sample, and the overall volume expands.

(b) Since the helium expels the air in the sample, the sample simultaneously floats up.

(c) Helium enters the sample and immediately escapes because helium has a lower specific gravity than air. This is due to the buoyancy of helium at that time.

(d) Adding helium improves the pressurization properties of the sample.

(e) Disturbance of the sample due to helium gas pressure.

As a result of various experiments, the following phenomena were observed.

Phenomenon 1: Spray helium on the sample surface to return it to an air atmosphere without any lifting, and then return to the helium atmosphere, which causes cracks on the sample surface and causes the sample to float.

Phenomenon 2 Normal helium gas (300mmAq flow rate 200c.c./min)
Even if you change the conditions and lower the helium gas pressure and flow rate, the floating phenomenon remains the same.

Phenomenon 3: The raised position of the sample appears immediately upon entering the helium atmosphere. The position where the lifting is most severe is approximately at the center of the space.

It is important to note that there are no cracks on the helium gas outlet side.

Phenomenon 4: When argon gas (specific gravity relative to air: 1.380) is used instead of helium, cracks in the sample do not disappear.

Phenomenon 5 Pressurize the sample onto a smooth iron plate (approximately 60
Helium gas (pressure: 2 kg/cm ² , flow rate: 1/2 kg/cm ² ) was pressed onto the surface of the sample to a thickness of approximately 5 mm.
When the sample temperature (min) is approached, similar cracks occur on the sample surface. Furthermore, cracked sample fragments tend to slide on the iron plate.

From the above, the following can be understood.

(1) From Phenomenon 1, it can be seen that the pressurization performance is not improved by adding helium.

(2) Cracks do not disappear even if the helium gas conditions that maintain the helium atmosphere are lowered (phenomenon 2), so this is not the cause of the cracks. However, if the helium atmosphere is eliminated and a completely air atmosphere is created, it is natural that the sample surface will not rise even without helium blowing.

(3) From Phenomenon 3, it can be seen that the presumed cause is not c.
This can be understood from the fact that the sample in the helium atmosphere under the beryllium window does not crack on the exit side, but rather the phenomenon occurs when it comes into contact with the helium atmosphere.

(4) This phenomenon is not unique to the sample forming process of the X-ray analyzer mentioned above, but generally, when helium gas is applied to powder in air, cracking and lifting phenomena always occur. However, this is only possible when the powder is under low pressure.

From the above, when helium gas is blown onto a sample containing air, the helium gas enters the sample and expels the air in the sample. At this time, a gas flow occurs within the sample, which causes the sample to float, resulting in cracks on the sample surface. Therefore, when the sample is molded while supplying helium gas through the helium supply pipe 12 as in the present invention, the helium inside and outside the sample maintains an equilibrium state or a state close to it in the space Q, so that the plane is not destroyed. .

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional continuous fluorescence X-ray analyzer, Fig. 2 is a schematic view showing an embodiment of the X-ray analyzer according to the present invention, and Fig. 3 is a partially enlarged sectional view of Fig. 2. be. 1... Container, 2... Shaft, 3... Wheel, 4...
...Hotupa, 5...First shoe, 6...Second shoe, 7...Beryllium foil window, 8...Spectroscopy room,
9, 10... Goniometer, 11... Powder sample,
12... Helium supply pipe.

Claims (1)

[Claims for Utility Model Registration] (1) A powder sample is continuously supplied onto a rotating wheel, and is pressed against the surface of the rotating wheel using a shoe provided at a fixed position opposite to the wheel surface to flatten the sample. In an X-ray analyzer that analyzes sample components by detecting fluorescent X-rays generated by irradiating X-rays onto the flat surface of the shoe, An X-ray analysis device characterized by being provided with a means for feeding the same gas as a gas having a small X-ray absorption capacity filled into an irradiation position. (2) The X-ray analysis apparatus according to claim 1, wherein the gas is helium gas.