JPH04201411A - Aggregate cooling device - Google Patents

Abstract

PURPOSE:To obtain an aggregate cooling device, the cooling efficiency of which is high and which is excellent in safety and economical efficiency, by a constitution wherein low humid air is fed through blasting ports into a cooling tower and aggregate to be cooled is charged from above the cooling tower under the condition that a disperser is rotated. CONSTITUTION:An enlarging part 11 divergent upwards is formed at the upper part of a cooling tower 10, at the lower part of which a contracting part 12 convergent downwards is formed. Above the enlarging part 11, a second conveyor 8, with which aggregate is fed to a hopper 29, is installed, while below the contracting part 12, a third conveyor 9, onto which the cooled aggregate falls down, is installed. On radially extending beams 14 fixed at the upper end part in the cooling tower 10, the axis 16 of a near conical disperser 15 is realisably supported on the top face of the beams 14 through a bearing 17 concentric to the cooling tower 10 so as to transmit the torque of a motor, which is provided on the top face of the beams 14, through a chain 21 to the disperser 15. In a cut-out device 26, a gate main body 24 is attached to and detached from the lower end of the contracting part 12 by raising and lowering a piston rod 22. Further, at the lower end of the contracting part 12, a plurality of blasting ports 27 are provided, to which an air feeding device 28 is connected.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an aggregate cooling device.

[Conventional technology]

As shown in Figure 5, the Baccha Plant l measures the materials that make up concrete, such as cement, water, sand, gravel, and admixtures to improve the fluidity and other properties of concrete, in a predetermined ratio. This is a plant for producing concrete by putting the sand into a mixer and mixing it.Generally, sand,
Aggregate 3 such as gravel is supplied from a stockyard 2 in which aggregate 8 is stored via a conveying device 4.5 such as a conveyor.

Concrete produced at Batcha Plant 1 is either transported to the pouring site and poured, or, especially in large-scale concrete structures, large temperature changes occur in the concrete after pouring due to the heat of hydration of the cement. In some cases, cracks may occur due to this, which may impede the functionality, durability, etc. of the structure.

As a means to solve such problems, there is a brecooling method in which concrete materials such as aggregate 3, cement, and water supplied to the buffing plant 1 are cooled in advance to suppress the temperature at which the concrete is kneaded.

Conventionally, the main means of cooling aggregate 3 used for pre-cooling of concrete are: ■ Cooling with cold air (
■ Cooling by sprinkling or submerging cold water (chilled water cooling), ■ Cooling with cryogenic liquid nitrogen (liquid nitrogen cooling), ■ Exhausting the air in the container filled with aggregate 3 to near vacuum, There is cooling that lowers the boiling point of water to near room temperature and uses the heat of vaporization at that time (vacuum cooling).

[Problems to be solved by the invention] The main problems with each cooling means are listed below.
It is as follows.

■Cold air cooling - Uniform cooling of aggregate 3 is difficult.

・Poor cooling efficiency.

・A large-scale cooling plant is required.

■Cold water cooling ・A large-scale cooling plant is required.

・There are many incidental facilities (water supply equipment, drainage equipment, turbid water treatment equipment, dewatering equipment, etc.).

■Liquid nitrogen cooling ・Running costs are high.

- Difficult to handle due to high pressure and extremely low temperature.

・There is a lot of cooling loss.

■Vacuum cooling - Uniform cooling of aggregate 3 is difficult.

・Equipment costs are high.

・Surface water management is difficult.

In view of these circumstances, the present invention aims to provide an aggregate cooling device that has high cooling efficiency and is excellent in safety, economy, etc.

[Means for Solving the Problems] The present invention includes a hollow cooling tower, a conveying device for feeding aggregate into the cooling tower from above, and a rotating shaft extending vertically provided in the upper part of the cooling tower. A device comprising a disperser, a cutting device provided at the bottom of the cooling tower, a conveying device for conveying the aggregate discharged from the cooling tower, and an air outlet connected to the cooling tower. It is.

[Function] When low-humidity air is supplied from the air outlet into the cooling tower, the disperser is rotated, and the aggregate to be cooled is thrown into the cooling tower.
The aggregate is uniformly distributed in the radial direction of the distributor, and is suspended in the cooling tower by the low-humidity air.

At this time, when the low-humidity air comes into contact with the surface of the aggregate, the moisture on the surface of the aggregate evaporates, and the temperature of the aggregate decreases due to the latent heat of vaporization when the moisture evaporates.As a result, the aggregate is cooled uniformly.

[Example] Hereinafter, the present invention will be described in detail based on the drawings.

Figures 1 to 4 show an embodiment of the present invention. A storage base 7 is installed between the stockyard 2 and the aggregate 3 installed underground in the stockyard 2.
A first conveyor for transportation; 8 is a conveyor (conveying device) for carrying the aggregate 3 carried out by the first conveyor 7 to the storage base 6; 9 is a conveyor for transporting the aggregate 3 from the storage base 6 to the upper part of the batcher plant l; A third conveyor (conveying device) for conveying is shown.

A cylindrical cooling tower IO extending in the vertical direction is installed in the storage base 6.

An enlarged portion 11 that expands upward is formed at the top of the cooling tower IO, and a contracted portion 12 that fits downward is formed at the bottom.

Above the enlarged part ll, the head part of the second conveyor 8 is
Further, a tail portion of the third conveyor 9 is installed below the reduction portion 12.

A beam 14 extending in the radial direction is fixed to the upper end portion of the cooling tower IO, and a shaft portion IB extending downwardly of the distributor 15 having a substantially umbrella shape is attached to the upper surface of the beam 14 via a bearing 17 to connect the cooling tower IO. An endless chain 21 is wound around a sprocket 19 of the motor 18, which is supported concentrically with the beam 14, and a sprocket 20 fixed to the shaft portion 16, so that the rotational force of the motor 18 is transmitted to the distributor 15. to be able to do so.

A fluid pressure cylinder 23 having a piston rod 22 extending downward is attached to the lower surface of the beam 14, and a connecting rod 25 extending upward is fixed to the upper end of the gate 24 having a conical shape that tapers upward. Furthermore, the upper end of the connecting rod 25 is connected to the lower end of the piston rod 22 to form the cutting device 2B.

When the cutting device 126 raises the piston rod 22, the gate body 24 comes into contact with the lower end of the contracted portion 12, and the lower end of the cooling tower IO is blocked, and when the piston rod 22 is lowered, , gate 24
is separated from the lower end of the reduced portion 12, so that the lower end of the cooling tower IO is opened.

Further, a plurality of air outlets 27 are provided at the lower end of the reduced portion 12 and penetrate through the air outlet 27 in a tangential direction.
Connect 8.

In addition, 29 in the figure is a charging hopper for guiding the aggregate 3 falling from the head portion of the second conveyor 8 directly above the disperser 15. Inside the charging hopper 29, a measuring device for weighing the aggregate 3 and a weighing device for weighing the aggregate 3 are installed. A cutting device is included.

The operation of the apparatus of this embodiment will be explained below.

When cooling the aggregate 3 during the production of ready-mixed concrete, the air supply device 28 is operated to supply low-humidity air from the air outlet 27 into the cooling tower 10, and the air is supplied into the cooling tower 10 from below to above. A swirling flow S of low-humidity air that rises while swirling is formed, and the motor 18 is driven to rotate the disperser 15.

At this time, the lower end of the cooling tower IO is closed by the cutting device 26.

In this state, the aggregate 3 to be cooled is transferred to the first conveyor 7, the second conveyor
When a predetermined amount of aggregate 3 is conveyed to the containment tower 6 by the conveyor 8, the aggregate 3 passes through the input hopper 29, is evenly distributed in the radial direction of the rotating body 15, and then falls.

The aggregates 3 that have fallen into the cooling tower IO are blown up into the air by the swirling flow S of low-humidity air and become suspended, and when the low-humidity air comes into contact with the surface of the aggregates 3, the surface of the aggregates 3 is The temperature of the aggregate 3 is lowered by the latent heat of vaporization when the moisture vaporizes, and as a result, the aggregate 3 is uniformly cooled.

In addition, the air that has removed moisture from the surface of the aggregate 3 is transferred to the cooling tower 1
It is discharged to the outside from the top of 0.

Once the aggregate 3 has been cooled by letting low-humidity air flow in for a certain period of time, the supply of low-humidity air by the air supply device 28 is stopped, and the aggregate 3 that has been in a floating state is moved to the shrinking section 12. Further, the cutting device 26 opens the reduction section 12 to allow the aggregate 3 to fall one by one onto the tail section of the third conveyor 9, and the cooled aggregate 3 is conveyed to the upper part of the batcher plant l by the third conveyor 9. and produce ready-mixed concrete.

In this way, in the apparatus of this embodiment, the aggregate 3 is cooled by the latent heat of vaporization when the moisture on the surface of the aggregate 3 evaporates, so the cooling speed and cooling efficiency are improved compared to conventional cold air cooling. Moreover, since it does not require large-scale incidental equipment such as hot water treatment equipment or draining equipment, the equipment scale is smaller and the equipment cost is lower than that of cold water cooling.

Furthermore, it is extremely clean as it uses only the water and air on the surface of the aggregate, and the equipment is safe as there is no risk of oxygen deficiency in liquid nitrogen cooling or damage to the pressure vessel in vacuum cooling. In addition, especially in the case of fine aggregate, the surface water content of the fine aggregate is reduced by the evaporation of water, making it easier to control the quality of concrete. It is advantageous for concrete break-cooling because it can increase the amount of water.

Note that the aggregate cooling device of the present invention is not limited to the above-described embodiments, but may be configured to provide the aggregate cooling device near the stockyard to cool the aggregate and then store it. Alternatively, an aggregate cooling device may be provided in a batcher plant to cool the aggregate transported to the batcher plant and then produce ready-mixed concrete, or a plurality of aggregate cooling devices may be installed in parallel. It goes without saying that batch processing can be carried out continuously, and that various changes can be made without departing from the gist of the invention.

[Effects of the Invention] As explained above, according to the aggregate cooling device of the present invention,
Various excellent effects can be achieved as described below.

■ Since it uses the heat of vaporization of moisture on the surface of aggregates caused by low-humidity air, the cooling speed and cooling efficiency are higher than conventional cold air cooling.

■ Because it does not require large-scale incidental equipment such as turbid water treatment equipment or draining equipment, the equipment scale is smaller and the equipment cost is lower than cold water cooling.

■ It is extremely clean as only the water and air on the surface of the aggregate is used, and the equipment is safe and economical as there is no risk of oxygen deficiency in liquid nitrogen cooling or damage to pressure vessels in vacuum cooling. Excellent in sex.

■ Particularly in the case of fine aggregate, the surface water content of the fine aggregate is reduced by the evaporation of water, making it easier to control the quality of concrete.Also, since the amount of mixing water with cold water can be increased accordingly, it can be used as a pre-cooling agent for concrete. It will be advantageous.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the aggregate cooling device of the present invention with the lower part of the cooling tower closed, and Fig. 2 is an embodiment of the aggregate cooling device of the present invention with the lower part of the cooling tower open. FIG. 3 is a cross-sectional view of FIG. 1 taken along the ■-■ arrow in FIG. It is a layout diagram showing an example. In the figure, 8 is a second conveyor (conveying device), 9 is a third conveyor (conveying device), 10 is a cooling tower, 15 is a disperser, 16
26 represents a cutting device, and 27 represents an air outlet.

Claims (1)

[Claims] 1) A hollow cooling tower, a conveying device for feeding aggregate into the cooling tower from above, a distributor having a rotating shaft extending vertically provided in the upper part of the cooling tower, and a dispersion device in the lower part of the cooling tower. What is claimed is: 1. An aggregate cooling device comprising: a cutting device provided therein; a conveying device for conveying aggregate discharged from the cooling tower; and an air outlet connected to the cooling tower.