JPH02170037A - Measuring instrument for aggregate surface water - Google Patents

Abstract

PURPOSE:To speed up measuring operation and to adapt the measuring instrument to the manufacture cycle of ready mixed concrete by feeding an aggregate sample in a cylindrical body where water is supplied and measuring the surface water rate of the aggregate automatically by using its water level variation. CONSTITUTION:While the lower opening of the cylindrical body 5 is closed with a bottomed lid 8, a proper amount of water is poured, and its water level is measured by a distance sensor 15, whose measurement data is sent to a microcomputer MCPT 35. Then the aggregate sample in a tank 2 is sampled 29 by a proper amount, its weight is measured 21, and the measurement data is sent to the MCPT 35 while the sampled aggregate is fed in the cylindrical body 5. Then the water level which is raised by the fed aggregate is measured by a sensor 15 after air bubbles are dispersed, and the measurement data is sent to the MCPT 35. The MCPT 35 calculates the aggregate surface water rate from the set specific gravity of the water, the surface dry specific gravity of the aggregate, the internal diameter of the cylindrical body, and measurement data.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an aggregate surface water measuring device for measuring surface water turbines of aggregates such as sand and gravel.

[Conventional technology] When ready-mixed concrete is manufactured using a batcher plant, concrete materials such as sand, gravel, cement, water, and admixtures are mixed in a fixed ratio, but the ratio of the amount of water to the amount of cement is It is known to have an important effect on concrete strength. Therefore, when measuring water according to the mix of concrete to be manufactured, it is necessary to take into account the surface water of the aggregate adhering to the surface of sand, gravel, etc.

Conventionally, there have been methods using electrostatic capacitance, infrared rays, neutron beams, etc. to measure the surface water content of aggregates. Also, J
In IS, a measuring method based on JISA All [Method for testing surface water content of fine aggregate J, JISA1125 "Testing method for water content of aggregate and Test method for surface water content based on water content" is known.

[Problems to be Solved by the Invention] However, in many devices that measure surface water percentage by applying electrostatic capacitance, infrared rays, neutron beams, etc., the detector is brought into contact with aggregate, so Measurement accuracy decreases when materials adhere to the aggregate or the particle size and packing density of the aggregate change, and furthermore, in the case of aggregate containing salt, there is a large variation in measurement values, making it impossible to measure accurately. . In addition, the measuring device based on JIS has the disadvantage that it takes time to manually measure weight and capacity using experimental equipment, and cannot keep up with the cycle time of ready-mixed concrete production.

Therefore, in view of the above points, the present invention aims to increase the surface water content of aggregate by J
The purpose of this invention is to propose an apparatus for measuring aggregate surface water that can automatically measure water in a short time while complying with the measurement method based on IS.

[Means for Solving the Problems] In order to achieve the above object, the present invention fixes a cylindrical body with a constant inner diameter, opens a lower opening at the bottom of the cylindrical body,
A distance sensor is provided at the first position of the cylindrical body to measure the water level inside the cylindrical body, and a weight measurement device is provided to measure the weight of sampled aggregate and to feed it into the cylindrical body. The present invention provides an aggregate surface water measuring device characterized by having a microcomputer that calculates the surface water percentage of the aggregate by calculating the data measured by the distance sensor and the weight measuring means. be.

[Function] In the aggregate surface water measuring device according to the present invention, first, an appropriate amount of water is poured with the lower opening of the cylindrical body closed with the bottom cover, and the water level is measured by a distance sensor. and sends the measurement data to the microcomputer. Next, an appropriate amount of aggregate sample is sampled, its weight is measured by a weight measuring means, the measured data is sent to a microcomputer, and the sampled aggregate is gently placed into the cylindrical body. Then, after the air bubbles are released, depending on the aggregate that is added.”
- Measure the rising water level again using the distance sensor and send the measured data to the microcomputer. In the microcomputer, the specific gravity of water that has been entered in advance,
The aggregate surface water is calculated by executing a surface water wheel calculation program from the surface dry specific gravity of the aggregate, the inner diameter of the cylindrical body, and the measured data.

[Example] Embodiments of the present invention will be described below based on the drawings.

A surface water measuring device main body 1 for measuring the surface water percentage of aggregates has its components housed in a frame 4 on a support member 3 provided near the bottom of an aggregate storage tank 2 of a batcher plant. To explain the components one by one, near the center of the frame 4, there is a cylindrical body 5 whose inner diameter has been machined so that the internal volume can be accurately determined if the height level is known. It's a solid foundation. A bottom cover 8 is attached to the lower part of the cylindrical body 5 for opening and closing the lower opening. An arm 10 having a mounting piece 9 erected thereon is fixed to the bottom cover 8, and the mounting piece 9 is pivotally supported by a shaft 12 on the support piece 9 fixed to the cylindrical body 5, and the bottom cover 8 is rotatable about the shaft body 12 as a fulcrum. The tip of the piston rod 14 of the air cylinder 13, which is accessible to the support member 6, is connected to the tip of the arm 10, and the lower opening of the cylindrical body 5 is opened by the bottom cover 8 as the piston rod 14 of the air cylinder 13 expands and contracts. It is supposed to be blocked and opened. A gasket (not shown) is attached to the portion where the cylindrical body 5 and the bottom lid 8 come into contact, so that the bottom of the cylindrical body 5 is completely sealed when the bottom lid 8 is closed.

An ultrasonic sensor 15, which is a distance sensor, is fixed to the frame 4 located above the cylindrical body 5.
The water level is measured by emitting ultrasonic waves into the water poured into the cylindrical body 5, catching the ultrasonic waves reflected from the water surface, and measuring the time from when the ultrasonic waves are emitted until they are reflected. be.

In order to more accurately measure the water level with the ultrasonic sensor 15, a dividing plate 16 is provided on a part of the cylindrical body 5 as shown in FIG. It is preferable to branch a thin tube 17 with a constant inner diameter from the side of the body 5 and measure the area where the influence of ripples on the water surface is as small as possible. In addition, when installing the surface water measuring device main body 1, it is preferable to use anti-seismic rubber or an anti-seismic mechanism to create a structure that is not affected by vibrations of the batcher plant main body as much as possible.

A water tank 18 is provided above the cylindrical body 5, and a valve 2 is provided on a water injection pipe 19 connected to the lower part of the water tank 18.
Water can be poured into the cylindrical body 5 from the water injection pipe 19 by opening and closing the water injection pipe 19. Reference numeral 21 denotes a weight measuring means for measuring the weight of the sampled aggregate sample.
3 is rotatably supported by a shaft 24, a load cell 25 is mounted and fixed on the upper surface of the plate 23, and a weighing pan 26 is attached thereon. Then, the piston rod 28 of the 44-digit air cylinder 27 is mounted on the support member 6.
Attach the tip of the plate near the center of the lower surface of the plate 23,
By expanding the piston rod 28 of the air cylinder 27, the weighing pan 26 is tilted as shown by the two-dot chain line in FIG.
This allows the sampled and measured aggregate to be put into the cylindrical body 5.

Reference numeral 29 denotes an aggregate sampling device provided at the lower part of the aggregate storage tank 2, and the aggregate sampling device 29 has a pipe 31 having a notch 30 on the upper surface inserted into the lower part of the aggregate storage tank 2. One end of the air cylinder 31 faces the weighing pan 26, and the extruded piece 34 fixed to the tip of the piston rod 33 of the air cylinder 32 provided at the other end causes the air to fall from the notch 30 into the pipe 31 and accumulate in the pipe. The aggregate sample is pushed out and dropped onto a weighing pan 26.

It should be noted that this aggregate sampling device is not limited to the above-mentioned structure in any way, and the point is that the aggregate storage tank 2 may be any device as long as it can sample the discharged aggregate.

35 is a microcomputer that performs arithmetic processing on various data, and the microcomputer 35 is connected to a CPU 36.
It is connected to the ultrasonic sensor 15 and the load cell 25 via AD converters 38 and 39, and the data measured by the ultrasonic sensor 15 and load cell 25 is input into the CPU 36 and stored in the aggregate. Programmed to calculate surface water percentage. Additionally, there is a setting input section 40 for setting and inputting initial data such as specific gravity of water, surface dry specific gravity of aggregate, inner diameter of cylindrical body 5, etc. required for calculating aggregate surface water percentage, and a display for displaying processing results. A device 41 is connected. Furthermore, it is also connected to an operation panel 42 so that the calculated aggregate surface water wheel can be fed back to the material metering of the plant.

Therefore, when measuring the surface water of aggregate, the specific gravity (9w) of water (when performing highly accurate calculations taking water temperature into account), bone The specific gravity (G) of the material in the surface dry state, the inner diameter of the cylindrical body (
D cm) is set and input in advance. And water tank 1
An appropriate amount of water is injected into the cylindrical body 5 by controlling the opening and closing of the valve 20 of the water injection pipe 19 of 8. After water injection, ultrasonic sensor 1
5 emits ultrasonic waves toward the water surface, measures the time until the reflected waves return from the water surface, and calculates the distance LL (cm) from the ultrasonic sensor 15 to the water surface using the following formula.

Measurement distance LL (cm) = Measurement time x Sound velocity / 2 Next, the piston rod 33 of the air cylinder 32 of the sampling device 29 is extended, and the sampling aggregate that falls from the notch 30 into the pipe 31 and accumulates inside the pipe is removed. piston loft 3
It is pushed out by the extrusion piece 34 at the tip of No. 3 and dropped into the weighing pan 26 of the weight measuring means 21. When the aggregate is transferred to the weighing pan 26, the aggregate weight ws sampled by the load cell 25
(g) is measured.

When the weighing of the aggregate is completed, the piston rod 28 of the air cylinder 27 is extended, the weighing pan 26 is tilted, and the aggregate on the weighing pan 26 is gently introduced into the cylindrical body 5 to eliminate air bubbles in the aggregate. After dispersing the water, the ultrasonic sensor 15 measures the distance L2 (cm) between the water surface inside the cylindrical body 5 and the ultrasonic sensor 15 again. At this time, the water level is rising according to the amount of aggregate added.

These measurement data are taken into the microcomputer 35, and the surface water percentage P% is calculated using the following formula.

The amount of sampled aggregate Ws (g) corresponds to surface water P''100 in surface-dry sand.

This is because the amount of water replaced by the sampling aggregate Vs (g) is the sum of the amount of water replaced by surface dry sand and the amount of surface water. From this formula we get: At this time, Vs is the amount of change in the water level in the upper body 5 (L
1-L2), and Vs= (LL-
L2) is calculated as Xπ(D/2)Xpw.

In this way, by measuring the difference in water level in the cylindrical body 5 before and after the sampling aggregate is introduced, the surface water percentage of the aggregate can be easily calculated. In addition, although it is desirable that the amount of water injected into the cylindrical body 5 be a constant amount, since the water level is measured each time water is injected, it is not necessary to keep the amount constant, and the amount of water remaining in the cylindrical body 5 is also measured at the next time. It is easy to operate because it does not affect the environment, and measurements can be performed quickly and automatically.

When the measurement of the surface water content of the aggregate is completed, the piston rod 14 of the air cylinder 13 is contracted, the bottom cover 8 of the cylindrical body 5 is opened, and the aggregate inside is discharged together with water. At this time, it is preferable to inject water from the water injection pipe 19 to clean the inside of the cylindrical body 5 and discharge the remaining aggregate.

[Effects of the Invention] As described above, in the aggregate surface water measuring device according to the present invention, it is possible to automatically measure the surface water percentage of aggregates using a calculation method based on JIS, and Since the surface water content of the concrete can be measured quickly, it is fully compatible with the production cycle of ready-mixed concrete.

Furthermore, since the water level in the cylindrical body 5 is measured every time the surface water content of the aggregate is measured, the surface water content can be accurately measured without being affected even if water remains in the cylindrical body 5. It is something that can be done.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal front view of the aggregate surface water measuring device according to the present invention, and FIGS. 2 and 3 are partially longitudinal front views showing other embodiments of the cylindrical body of the aggregate surface water measuring device. It is a diagram.

Claims (1)

[Claims] A cylindrical body with a constant inner diameter is fixed, a bottom cover is provided at the bottom of the cylindrical body to open and close the lower opening, and a distance is provided above the cylindrical body to measure the water level inside the cylindrical body. In addition to providing a sensor, a weight measuring means is provided to measure the weight of sampled aggregate and put it into the cylindrical body, and the data measured by the distance sensor and weight measuring means is calculated and calculated to determine the surface water content of the aggregate. An aggregate surface water measuring device characterized by being equipped with a microcomputer that calculates.