JP2923800B2 - Ice weighing accuracy improvement method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for improving the accuracy of ice weighing by an ice weigher used in a concrete raw material blending plant.

[Conventional technology] In a concrete material mixing plant, in addition to coarse aggregate, fine aggregate, cement, and the like as concrete raw materials, ice is measured and discharged in a required amount, and these are kneaded with a mixer to produce concrete. It is.

As shown in FIG. 4, the ice weighing device for weighing ice includes a screw conveyor 4 for transporting ice in an ice storage 3 above an ice weighing device 1 provided with a release gate 2 at its lower part so as to be openable and closable. The screw conveyor 4
A measuring valve 5 is provided at the cutout of the device, and the ice from the screw conveyor 4 is charged into the ice measuring device 1 or stopped by opening and closing the measuring valve 5. Reference numeral 6 denotes a load cell of the ice weighing device 1.

When the ice is supplied from the screw conveyor 4 to the ice weighing device 1, the ice is supplied from the screw conveyor 4 to the ice weighing device 1 while being measured by the measuring valve 5 until the target weighing value is reached. Up to about 90% of the target weighing value, as a large charging area, the ice from the screw conveyor 4 is measured by the measuring valve 5 so that a large amount of ice is continuously charged into the ice weighing device 1, and thereafter, until the target weighing value is reached. , As a small charging area, ice is measured little by little and charged into the ice measuring device 1 while the measuring valve 5 is opened and closed intermittently.

[Problems to be Solved by the Invention] However, the ice used for mixing the raw materials for concrete is
Usually, sliced ice sliced into sliced ice or flake ice sliced into shaved ice is used, so that the ice slices stick to each other during supply and are not easily regulated. Therefore, when a large amount of ice is weighed in a short time, in the case of intermittently weighing ice to a target weighing value in a small charging area as in the conventional method described above, the actual weighing value and the target weighing value Was large and the measurement could not be performed accurately.

Therefore, the present invention is intended to improve the measurement accuracy so that a large amount of ice is measured in a short time so that the target measurement value is obtained.

[Means for Solving the Problems] In order to solve the above-described problems, the present invention provides a method in which cold water can be injected in addition to charging ice from a screw conveyor to an ice weighing device, and a weighing amount close to a target weighing value. In the large charging area, the metering valve at the screw conveyor cut-off port is used for measurement, and then, in the small charging area where the final metering is performed, the cold water is measured, and the measured value of the cold water is used to supplement the final metering amount. In addition, in the above-mentioned large charging area, the screw feeding speed of the screw conveyor is made variable and the measuring valve is opened and closed, the metering valve is fully opened at a high speed of the screw conveyor, the metering valve is fully opened at a low speed of the screw conveyor, and the metering valve is at a low speed of the screw conveyor. The intermittent opening and closing may be performed in stages to measure the ice.

[Action] Since the final measurement amount that reaches the target measurement value is supplemented by the measurement value of the cold water, compared to the case where the final measurement is performed by intermittently opening and closing the flake ice that is not easily rectified during supply by intermittent opening and closing of the measurement valve. It is easy to approach the target measurement value, and the measurement accuracy can be improved. If the large feeding area is measured stepwise by changing the feeding speed of the screw conveyor, a large amount of ice can be measured in a shorter time.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the outline of an apparatus for carrying out the method of the present invention. The screw conveyor 4 that conveys ice from the ice storage 3 is faced, and a measuring valve 5 is provided at the cutout of the screw conveyor 4, and the ice conveyed by the screw conveyor 4 and put into the ice measuring device 1 is measured by a measuring valve. 5
The chilled water pipe 8 faces the position above the ice weighing device 5, and a chilled water measuring valve 9 is attached in the middle of the chilled water piping 8. To do. Reference numeral 6 denotes a load cell.

When the ice is weighed by putting ice into the ice weighing device 1, the former is divided into a large weighing region I and the latter is a small weighing region. II, in the large charging area I, the screw conveyor 4 is operated and the measuring valve 5 is opened so that the ice conveyed by the screw conveyor 4 is continuously charged while being measured by the measuring valve 5, , Small input area
In II, the ice metering valve 5 is closed, and cold water is introduced instead of ice to make up the final metered amount with cold water. In other words, a small input area close to the final target weighing value
In II, the chilled water sent through the chilled water pipe 8 is metered in by the metering valve 9, and the weighing of the ice thrown in the large throwing area I is measured in the small throwing area II instead of the ice. Add weight to reach target weighing value. Since cold water is used in the small input area II, accurate measurement can be performed and the accuracy of the actual measured value can be increased, and an error between the target measured value and the measured value can be reduced.

The relationship between the weighing time and the weighing weight in the above weighing is as shown in FIG. 2, and since the final weighing amount of the ice weighing in the ice weighing device 1 is supplemented by the cold water weighing, the weighing accuracy can be improved and a large amount of weighing can be performed in a short time. Ice weighing can be performed.

In the above-described embodiment, the case where the measuring valve 5 is fully opened in the large charging region I and the ice sent from the screw conveyor 4 is continuously charged into the ice measuring device 1 has been described. Ice weighing can be performed stepwise.

FIG. 3 shows an example in which the large charging area I is divided stepwise. The screw conveyor 4 operates at high speed from the start of ice weighing until a predetermined time, and then switches to low speed operation. The valve 5 is fully opened until a predetermined time elapses after the screw conveyor 4 is switched to a low speed, and thereafter, the metering valve 5 is opened and closed intermittently so that ice is intermittently supplied. 4 is a first step S1 where the metering valve 5 is fully opened and the metering valve 5 is fully open. The screw conveyor 4 is a low speed operation and the metering valve 5 is fully open is a second step S2. The screw conveyor 4 is metered at a low speed. The part where the valve 5 opens and closes intermittently is the third step S3.

When the method of measuring the large charging area I step by step as described above is implemented, a large amount of ice can be measured in a short time in the first step S1 and the second step S2, and the screw conveyor 4 is operated at a low speed in the third step S3. In addition, since the cutting of the ice is intermittent, it is possible to improve the weighing accuracy by introducing the ice little by little at a low speed. In the small charging area II, cold water is used instead of ice as in the case of the above-described embodiment, and the cold water is measured to approach the final target value.

According to this embodiment, in the large charging area I, the feeding speed can be varied by the screw conveyor 4 and the opening and closing of the ice measuring valve 5 are combined. In the small charging area II, cold water is used.
The accuracy of weighing in the large input area I can be improved, and the small weighing area II can be used to supplement the final weighing using water supply, reducing the error that occurs between the target weighing value and the actual weighing value. As a result, the measurement accuracy can be improved.

[Effects of the Invention] As described above, according to the method for improving the accuracy of ice weighing of the present invention, the actual weighing section until the ice used for mixing the concrete raw material reaches the predetermined target weighing value is almost changed to the target weighing value. The ice weighing device is divided into a large charging area where the ice is poured into the ice weighing device up to a weighing value close to the weighing value, and a small charging area where the remaining final weighing amount is charged. In addition, since the final measurement is supplemented by cold water measurement, the final measurement can be quickly and accurately measured, and the difference (error) between the actual measurement value and the target measurement value can be reduced. And the weighing accuracy can be improved. Further, in the above-mentioned large charging range, a first step of increasing the feeding speed by the screw conveyor to fully open the ice measuring valve, and a second step of reducing the feeding speed by the screw conveyor to fully open the ice measuring valve. And a third for intermittently opening and closing the ice metering valve by lowering the feeding speed by the screw conveyor.
It is divided into steps, and the first step, the second step, and the third step are weighed in this order, and the cold water is measured in the small charging area. Measurement can be performed with high accuracy, and the measurement accuracy can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for performing the method of the present invention;
FIG. 2 is a measuring procedure diagram showing one embodiment of the method of the present invention, FIG. 3 is a measuring procedure diagram showing another embodiment of the method of the present invention, and FIG. 4 is a schematic diagram of a conventional ice measuring device. is there. 1 ... Ice meter, 2 ... Discharge gate, 3 ... Ice storage, 4 ... Screw conveyor, 5 ... Measuring valve, 8 ...
Chilled water piping, 9 ... Chilled water metering valve, I ... Large input area, II ... Small input area.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01G 13/00-13/08 G01G 17/00-17/06 B28C 7/00-7/14

Claims (2)

(57) [Claims] 1. A process of charging ice used for mixing concrete raw materials into an ice weighing device while weighing ice up to a weighing value that reaches the target weighing value so that the ice can be discharged from the ice weighing device at a predetermined target weighing value. It is divided into a large charging area where ice is charged up to the weighing value close to the target weighing value, and a small charging area where ice for the final weighing is charged.In the large charging area, ice fed by the screw conveyor is measured by a measuring valve. A method for improving the accuracy of ice weighing, comprising weighing and then measuring cold water with a cold water metering valve in a small charging area, and supplementing the final measurement with cold water. 2. A first step in which the metering valve is fully opened by increasing the ice feeding speed by the screw conveyor in a large charging area, and a second step in which the metering valve is fully opened by lowering the ice feeding speed. And a third step of intermittently opening and closing the metering valve by lowering the ice feeding speed so as to measure the ice by operating the first step, the second step, and the third step in this order. The method for improving ice weighing accuracy according to claim 1.