JP2594158Y2 - Moisture content measuring device for sand for ready-mixed concrete - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the moisture of sand to be added in the production of ready-mixed concrete using an infrared moisture measuring apparatus or the like.

[0002]

2. Description of the Related Art When producing ready-mixed concrete, for example, as shown in FIG. 1, sand stored in two storage tanks 1a and 1b is discharged to a measuring tank 8 and weighed, and a predetermined amount is cut out to a mixer 9. At the same time, a necessary amount of cement and water for fine adjustment are added and mixed, but it is necessary to measure in advance the amount of water contained in the sand to be mixed in order to obtain a required viscosity.

Conventionally, the moisture content of sand has been measured by a specific gravity method for measuring the specific gravity of sand (sample) collected at the time of discharging from a storage tank, or by evaporating water by infrared heating a sample inserted in a closed container. Although the absolute drying method for measuring the water content of the saturated water in the container has been performed, such a batch measurement takes an extremely long time, and one measurement requires about 15 minutes in the former case and about one hour in the latter case. It was extremely inefficient to make.

On the other hand, there is a method of continuously measuring the water content of sand in a storage tank by using a microwave measuring device, but it is not practical because the device is expensive and the accuracy is not so good. .

[0005] Further, there is a method in which sand discharged from a storage tank is collected in a saucer, moved to a measuring position of a separately provided infrared moisture meter, and the water content of the collected sand is measured.
There are problems such as that the measurement of moisture takes too much time due to the time schedule of the batcher, and that the sampling device including the moving device is complicated.

[0006]

SUMMARY OF THE INVENTION The present invention solves such problems in the prior art, and eliminates the need for a separate step such as sampling, and directly measures the water content of sand in a storage tank. It is an object of the present invention to provide an apparatus for measuring the moisture content of sand for ready-mixed concrete which can be measured in real time and continuously.

[0007]

That is, according to the present invention, a sight tube is mounted obliquely downward on a wall surface of a discharge part of a sand storage tank, and a tip measuring surface of the sight tube is connected to the sight tube. During ~
10-20 ° to the line perpendicular to the core wire
And a moisture meter installed in the sand for ready-mixed concrete, wherein a moisture meter is installed outside the peeping tube.

[0008]

The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is an explanatory view showing an example of a ready-mixed concrete manufacturing apparatus, FIG. 2 is a view showing a configuration of the present invention, and FIGS. In the drawing, reference numerals 1a and 1b denote storage tanks for sand 7, and a cylindrical tank which communicates the inside and outside of the storage layer 1 with a wall surface 3 of a funnel-shaped dispensing section 2 provided therebelow, as shown in a cross section in FIG. The viewing tube 4 is installed obliquely downward. Further, a moisture meter 5 such as an infrared moisture meter is attached to the peeping tube 4 by inserting a hood 6 provided in the moisture meter 5. In the figure, reference numeral 10 denotes a gate.

The mounting angle a of the viewing tube 4 installed at such a position (the inclination angle of the viewing tube formed by the viewing line center line c with respect to the horizontal line h) is preferably as large as possible. That is,
If the angle a is small, sand enters the sight tube 4 and remains in the tube without dropping even when dispensing. If it is too large, the length of the sight tube must be lengthened, and if it exceeds the measurement distance of the moisture meter 5, the measurement becomes inaccurate, and the head of the moisture meter 5 hits the wall 3 of the storage tank 1 and is difficult to attach. to become. From the results of experiments, it was found that it is preferable in the range of 30 ° ± 5 ° relative to a horizontal plane.

The tip surface 4a of the viewing tube 4 of the present invention has an angle b of 15 ° ± 5 ° with respect to the center line c of the viewing tube and the orthogonal line r.
In the range, the upper end of the end face 4a is inclined toward the inside of the storage layer. When the angle b decreases, that is, when the inclination of the tip end surface 4a approaches the orthogonal line r, sand enters the viewing tube, and
If it is too large, the measurement angle becomes large and sufficient measurement accuracy cannot be obtained. Therefore you in the above-mentioned range.

Note that the length of the viewing tube 4 is
It is preferable that b is located on or near a line extending from the periphery of the opening 11 to the payout gate 10. If the sight tube 4 is inserted too much, the abrasion is accelerated, and the outflow of sand is affected. The distance between the moisture meter and the object to be measured may be any distance that does not affect the measurement accuracy, and is preferably, for example, within 400 mm ± 50 mm.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A viewing pipe having an outer diameter of 115 mm and an inner diameter of 105 mm is installed on the wall surface of a funnel-shaped dispensing section provided below a storage tank at an angle of 30 ° with respect to a horizontal plane. Then, the tip protruded 110 mm into the storage tank.
Further, the angle b of the measurement surface at the tip of the viewing tube was set to 15 °. An infrared moisture meter with a hood was used as the moisture meter, and the hood was inserted and attached to the viewing tube. The distance between the sensor of the moisture meter and the measurement surface was set to about 450 mm.

Therefore, calibration curves were prepared by preparing samples having four types of water content. That is, the measurement object (hydrous sand)
A sample test is performed every time, and the correlation (calibration curve) between the moisture value (% moisture) obtained by the accurate measurement method by the absolute drying method and the sensor output (absorbance) of the infrared moisture meter is obtained in advance.
Then, when the moisture was measured by the device of the present invention, the results shown in Table 1 were obtained.

As is apparent from the results, according to the device of the present invention, the error is within the error range of 0.5% or less, which is considered to be practically acceptable. It can be seen that continuous measurement of the amount can be performed.

[0015]

[Table 1]

[0016]

As described above, according to the present invention, the water content of the sand discharged from the storage tank can be continuously measured in real time, and therefore, in the production of ready-mixed concrete, the water content is adjusted. Can be performed accurately.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of an apparatus for producing ready-mixed concrete according to the present invention.

FIG. 2 is an explanatory view showing an example of the configuration of the present invention.

FIG. 3 is an explanatory view showing an attached state of the sight tube according to the present invention.

FIG. 4 is an explanatory diagram showing a mounting state of the moisture meter in the present invention.

[Description of reference numerals] 1, 1a. 1b Storage tank 2 Dispensing part 3 Wall surface 4 Peeping pipe 4a Peeping pipe end face 4b Fine wire end position 5 Moisture meter 6 Hood 7 Sand 8 Measuring tank 9 Mixer 10 Gate 11 Opening

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kaoru Uemura 2-3-3 Horobetsu-cho, Noboribetsu-shi, Hokkaido Ueda Shokai Co., Ltd. (56) References JP-A-3-10145 (JP, A) JP-A Sho 62 -95125 (JP, A) JP-A-59-34135 (JP, A) JP-A-60-82255 (JP, U) JP-A-4-21847 (JP, U) JP-A-3-119751 (JP, U) (58) Fields surveyed (Int.Cl. ⁶ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 B01J 2/16 B01J 8/02

Claims (1)

(57) [Scope of request for utility model registration] 1. A peeping pipe is provided on the wall surface of the payout part of the sand storage tank.
Attach it obliquely downward and attach the tip of the sight tube
The measurement surface is set at 10 to 20 with respect to a line
° An apparatus for measuring the water content of sand for ready-mixed concrete, wherein the apparatus is inclined inward of the storage layer and a moisture meter is installed outside the peeping tube.