JPH0812146B2 - Fineness measuring machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fineness measuring instrument for continuously and automatically measuring fineness of powder, for example, cement required for stabilizing the quality of cement.

[0002]

2. Description of the Related Art Conventionally, a cement fineness measuring instrument of this type irradiates a flowing cement powder group with a laser beam in a dispersed state, collects scattered light from each powder produced at that time by a lens, and The diffraction image corresponding to each fineness that appears on the surface including the focal point is converted into an electric signal, and this is calculated to measure the fineness.

Therefore, when laser light is irradiated, if agglomerated and segregated substances are mixed in each cement powder constituting the dispersed cement powder group, the agglomerated and segregated cement powder is included. Since the fineness of the cement powder group is measured, it becomes impossible to accurately measure the fineness.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to agglomerate and segregate with each other in each cement powder constituting a dispersed cement powder group when the above laser beam is irradiated. It is to make things empty. As a result, it is necessary to be able to measure an accurate fineness.

Another object is to prevent the agglomerated and segregated cement powders from separating and mixing with each other and then agglomerating and segregating again while transporting them to the position to be irradiated with laser light.

Another object of the present invention is to transport a cement sample for measurement taken from a cement powder discharge port in the final step of a cement manufacturing apparatus to a fineness measuring machine installed at a position distant therefrom. It is to prevent the cement sample from aggregating and segregating.

The present invention relates to a fineness measuring machine in which a measurement sample supply pipe is connected to an upstream side of a measurement pipe intersecting with a laser beam via an inverted conical mixing hopper; along a conical surface of the mixing hopper. Then, a collision plate diagonally opposed to the measurement sample supply pipe is arranged, an ejector nozzle is provided in the measurement sample supply pipe in a direction obliquely opposed to the collision plate, and the measurement pipe is provided at the top of the mixing hopper. It is intended to achieve the above object by providing a connecting pipe to be connected and disposing the mixing flow nozzle around the top of the mixing hopper.

[0008]

Operation: The measurement sample of the powder collides from the outlet of the measurement sample supply pipe with the collision plate obliquely arranged along the inner surface of the cone of the inverse conical powder mixing hopper, and the aggregated and segregated powders are separated from each other. Disperse and mix.

The surface of the collision plate is always exposed by being repelled obliquely with respect to the surface of the collision plate, and is introduced into the top of the inverted conical mixing hopper.

An air flow ejected from a mixed flow nozzle facing the periphery of the top is made to act on the introduced cement powder to generate a mixed flow, and the cement powder in this state is subjected to another measurement of the thin tube through a communicating pipe. Send it into the pipe (measurement duct).

The inside of the measuring duct flows from the upstream side to the downstream side, and the cement particles are irradiated with laser light during the flowing, and the scattered light at that time is converted into an electric signal to measure the fineness. .

[0012]

EXAMPLE A measuring tube 1 and a laser beam 2 are provided so as to intersect with each other, and a sample supply tube 4 is connected to the upstream side of the laser beam 2 in the measuring tube 1 via an inverted conical mixing hopper 3.

The collision plate 5 is obliquely arranged on the conical surface 3a of the mixing hopper 3 and on the extension line 4e on the outlet side of the measurement sample supply pipe 4. The conical surface 3a may double as the collision plate 5.

One end of a communication pipe 7 is connected to the outside of the top 6 of the inverted conical mixing hopper 3 and the other end of the communication pipe 7 is connected to the upstream side of the measuring pipe 1.

An ejector nozzle 23 is provided in the sample supply pipe 4 so as to obliquely face the collision plate 5, and an ejector nozzle 8 is provided inside the top portion 6 of the inverted conical mixing hopper 3.
Is arranged toward one end of the communication pipe 7, and the top 6
The mixed flow nozzle 10 is faced from the outside to the inside in the surroundings of. By installing these ejector nozzles 23 and 8 and the mixed flow nozzle 10, a dispersed state can be improved. Further, the communication tube 7 can be made thinner than the sample supply tube 4 to enhance the dispersion effect.

Although not shown, a part of the cement powder, which is the final product in the cement manufacturing process, is continuously taken as a sample, and the sample is fed through the sample supply pipe 4 to the mixing hopper 3
Supply in the direction of arrow A1.

The cement powder sample supplied into the mixing hopper 3 is generally composed of powder particles 11 and agglomerated particles 12, which are extended lines 4e on the outlet side of the sample supply pipe 4 on the conical surface 3a. It collides obliquely with the collision plate 5 provided above with an inclination angle θ.

At this time, the agglomerated particles 12 are dispersed into a large number of powder particles 11, which immediately flow along the inclined surface of the collision plate 5 toward the apex 6 of the conical surface 3a in the direction of arrow A2, and the subsequent agglomeration. The flow of the particles 12 should not be prevented from directly impinging on the impingement plate 5.

The powder particles 11 flowing into the apex 6 of the conical surface 3a are brought into a mixed flow state by the air jetted from the mixing flow nozzle 10, so that the dispersed state of the powder particles 11 is further improved.

The powder particles 11 in the mixed flow state are sucked into the communication pipe 7 by the air flow ejected from the ejector nozzle 8 toward one end of the communication pipe 7, and moved to the upstream side of the measurement pipe 1.

Air is ejected from the ejector nozzles 13, 14 and 15 to the powder flow 11 which has been moved to the upstream side of the measuring pipe 1 to diffuse, and flows in the measuring pipe 1 toward its downstream side, and traverses this flow. The laser light 2 from the laser source 17 is radiated, and the scattered light at that time is condensed by a lens (not shown) and received by the photo detector 18, which is converted into an electric signal to measure the particle size distribution. Is.

Although the embodiment of the present invention has been described with reference to FIGS. 1 and 2, the present invention is not limited to this, and modifications and additions of partial structures may be made within the scope of the gist of the present invention. It is also possible to go and implement.

For example, the shape of the inverted conical mixing hopper 3 can be bowl-shaped if necessary. 1 and 2
Since a plurality of sample supply pipes 4 shown in FIG. 1 are connected to one mixing hopper 3, the cement fineness measuring device 1 of the present invention is
This is convenient when measuring the fineness of cement produced from multiple cement production equipment on a stand, but on the other hand, the route from each cement production equipment to this measurement equipment may become long and the proportion of aggregated particles may increase. Therefore, in this case, the measuring machine of the present invention can be connected to each cement manufacturing apparatus.

FIGS. 3 and 4 show an embodiment of this case,
Cement powder discharge pipe 20 in each cement manufacturing device
Double screw conveyors 21 and 22 are provided as an example of a supply device across the pipe, and a part of the cement powder flowing down in the discharge pipe 20 is captured by the double screw conveyor and transferred in the direction of arrow A4 to discharge the discharge pipe 20. It is discharged to the outside and introduced into the sample supply pipe 4.

The cement powder in the sample supply pipe 4 is sucked by the air ejected from the ejector nozzle 23, introduced into the mixing hopper 3, and collides with the collision plate 5 in the same manner as in the embodiment of FIGS. 1 and 2. , The aggregated particles 12 are dispersed and mixed, and the top 6
The mixed flow is formed by the air flowing into the portion and ejected from the mixed flow nozzle 10, and is introduced into the measuring tube 1 in that state.

Here, the laser light 2 from the laser source 17
And the scattered light corresponding to the particle size of the cement powder is condensed by a lens (not shown), and the photo detector 18
, And converts it into an electric signal to measure the fineness thereof.

The sample that has flowed downstream from the position of the laser beam 2 after the measurement of the fineness is processed by the fan 24 and the wind force A24 in the double screw conveyors 21 and 22 in the discharge pipe 20.
It is returned again to the cement powder flowing downstream from the position.

When the fineness of the cement powder discharged from a certain cement manufacturing apparatus was measured using the cement fineness measuring apparatus of the above-mentioned example, the residual amount of the powder having a size of 30 μm or more was 22.8%. . This is shown in FIG.
become.

Next, when the same cement powder was manually measured with a standard sieve for a long time, the remaining amount of powder of 30 μm or more was 22.5%. This is shown by the horizontal line 24 in FIG.

Therefore, the vertical line 25 and the horizontal line 2 in FIG.
The intersection point P of 6 is 22.8% when the particle size of the same cement powder is measured by the present invention, and is 22.5% when measured by a standard sieve.
%, Indicating that the measurement according to the invention is very close to the value measured with a standard sieve.

When the residual amount of particles of 30 μm or more was measured for the cement powder discharged from another cent manufacturing apparatus by the same method as described above, the intersection point p (1, 2,
3 to n) are obtained, and these intersections are concentrated on the diagonal line 26 indicating a group of points where the measured value according to the present invention and the measured value according to the standard sieve are equal, and from this, the measuring device according to the present invention is It can be seen that when the particle sizes of various cement powders are measured using the same, the values are almost the same as the values measured on the standard sieve in any case.

On the other hand, the above-mentioned conventional measuring machine, that is, the measuring machine which lacks the impingement plate provided along the conical surface according to the present invention and the apex portion of the conical surface facing the mixed flow generating device, is used. Using the same cement powder as above, 3
When the residual amount of particles of 0 μm or more was measured, Q (1, 2, 3 to n) shown by black dots in FIG. 5 were recorded, and these positions were largely apart from the positions on the diagonal line 26.

From this, it can be seen that the values were significantly different from the values measured by the standard sieve, and the accurate particle size was not shown.

[0034]

Since the present invention is constructed as described above,
It has the following remarkable effects. (1) Since the collision plate diagonally opposed to the measurement sample supply pipe is arranged along the conical surface of the mixing hopper, and the ejector nozzle obliquely opposed to the collision plate is provided in the measurement sample supply pipe, The powder sample in the sample supply pipe is sucked by the air ejected from the ejector nozzle and introduced into the mixing hopper, and obliquely collides with the collision plate to disperse and mix the agglomerated particles,
It immediately flows toward the top of the mixing hopper and does not prevent the subsequent stream of agglomerates from impinging directly on the impingement plate. (2) Since the mixing flow nozzle is disposed around the top of the mixing hopper so as to face it, the air jetted from the mixing flow nozzle creates a mixed flow state, and the powder sample is well dispersed. (3) The powder sample can be irradiated with laser light immediately after being well dispersed and mixed for measurement, and is not aggregated or segregated again while being transferred to the measurement position. Therefore, it is possible to accurately measure the fineness. (4) When the upstream side of the measurement sample supply pipe is combined with the outlet of the supply device arranged in the powder product discharge pipe, the powder sample is aggregated and segregated during the transfer of the sample from the discharge pipe to the supply pipe of the present invention. It is possible to reduce the phenomenon that occurs. The present invention is not limited to the measurement of particle size distribution of cement powder,
It goes without saying that it can be applied to various powders such as carbon black and toner.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of a portion of FIG.

FIG. 3 is a vertical sectional view of another embodiment of the present invention.

FIG. 4 is a right side view in which a part of FIG. 3 is cut.

FIG. 5 is a table showing a comparison between the fineness measured in the present invention and the fineness (%) measured with a standard sieve.

[Explanation of symbols]

 1 Measuring Tube 2 Laser Light 3 Mixing Hopper 4 Sample Supply Tube 5 Collision Plate 6 Apex 7 Communication Tube 8 Ejector Nozzle 10 Mixed Flow Nozzle

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G01N 15/02 Z 21/53 Z

Claims (4)

[Claims] 1. A fineness measuring instrument in which a measurement sample supply pipe is connected to an upstream side of a measurement pipe intersecting with a laser beam through an inverted conical mixing hopper; along a conical surface of the mixing hopper. A collision plate diagonally facing the measurement sample supply pipe is arranged, and the collision plate diagonally faces the measurement sample supply pipe.
Direction, an ejector nozzle is provided in the direction, a communication pipe that is connected to the measuring pipe is provided at the top of the mixing hopper, and a mixed flow nozzle is exposed around the top of the mixing hopper.
A fineness measuring instrument characterized by being provided. 2. The fineness measuring machine according to claim 1, wherein the collision plate is a conical surface of a mixing hopper. 3. The fineness measuring instrument according to claim 1, wherein the communication pipe is a narrower pipe than the measurement sample supply pipe. 4. The fineness measuring instrument according to claim 1, wherein the upstream side of the measurement sample supply pipe is connected to the outlet of a supply device which is arranged in the powder product discharge pipe.