JPH09314541A - Chiller for sand to be used for ready-mixed concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool sands in a short time for enhancing capacity per hour, simplify trouble of a chiller for cooling cold water due to the sands and simplify its maintenance. SOLUTION: A sand chiller stirs sands by a stirring chiller 2 and cools it by cold water. The cold water to be discharged from the stirring chiller 2 is put in a separation tank 8 for separating the sands. The cold water in the stirring chiller 2 is cooled by a chiller 1. The stirring chiller 2 comprises a cold water tank 3, a screw axis 4, and a draining discharge machine 14. The screw axis 4 fixes a spiral fin 6 and sends the sands to the draining discharge machine 14 by stirring the sands in the cold water tank 3. At the separation tank 8 and the discharging side of the stirring chiller 2, a bypass 9 for sand is provided. The bypass 9 comprises a sand pump 10 for sucking the cold water in which the sands in the separation tank 8 are mixed and a liquid cyclone 11. The sands to be discharged together with the cold water from the stirring chiller 2 to the separation tank 8 are separated from the cold water at the liquid cyclone 11 and supplied to the discharging side of the stirring chiller 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for cooling sand for producing cooled green concrete.

[0002]

2. Description of the Related Art It is important to lower the kneading temperature of ready-mixed concrete. In particular, in hot summer concrete having a daytime temperature of more than 25 ° C., various characteristics are improved by cooling. Hot-water concrete has the drawback that the slump becomes low, cracks occur when it hardens, and the strength decreases.

The drop in slump is due to the evaporation of water. For example, when the kneading temperature is 30 ° C, the slump 18c
It is said that the slump will be lowered by about 6 cm if a fresh concrete of m is transported by a truck agitator for about 1 hour. When the slump is reduced, the driving becomes difficult. This fresh concrete needs to be remixed by adding a cement paste. Further, ready-mixed concrete has a characteristic that the slump decreases as the temperature increases, even if the amount of water added is adjusted to be the same.

The cracks that occur when concrete hardens are due to the internal heat generation. The hydration reaction when the concrete hardens is an exothermic reaction. When heat is generated inside, there is a temperature difference between the inside and the outside surface of the concrete. The warmed interior expands thermally and the cooled exterior surface
Shrinks and cracks. Cracking of concrete causes significant adverse effects in all applications. In particular, dams, bridge piers installed in the sea, and bulkheads of nuclear reactors are fatal defects. In addition, hot concrete also has reduced strength when hardened. These adverse effects can be eliminated by cooling the ready-mixed concrete.

An apparatus for cooling added water has been developed as an apparatus for producing cooled ready-mixed concrete. However, even if the added water is cooled, the kneading temperature of green concrete cannot be lowered so much. The reason is that the amount of water added to green concrete is only 4 to 6% by weight of the total amount.

An apparatus for cooling cement added to ready-mixed concrete has also been developed. This device blows liquefied nitrogen gas into the cement to forcibly cool the cement. This device has the advantage that it can be cooled without adding water to cement, but has the drawback of significantly increasing running costs. This is because the amount of expensive liquefied nitrogen consumed is large. For this reason, this device can only be used for special ready-mixed concrete.

Approximately 20% by weight of sand is mixed with green concrete. By cooling the sand, the temperature of green concrete can be lowered. As a sand cooling device, a device for blowing liquid nitrogen into sand has been developed. However, this device, like the device that cools cement with liquid nitrogen,
There is a drawback that the running cost is extremely increased by consuming a large amount of expensive liquid nitrogen.

Devices have been developed for cooling aggregates using cold water. In this device, aggregate is transferred by a conveyor belt, and a cold water tank is arranged in the middle of the conveyor belt. In this device, an aggregate that is transported by being placed on a conveyor belt in cold water is brought into contact with the cold water to be effectively cooled.

The cooling device having this structure can also be used for cooling sand. However, the cooling of sand with this device has the drawback of significantly reducing the throughput. The reason is that a large amount of sand cannot be placed on the conveyor belt to cool it. Aggregates have larger grains than sand, and large voids are formed between them so that cold water can be effectively distributed. However, sand is a fine particle and has almost no gap, and cold water cannot be circulated inside. Therefore, the cooling device having this structure has a drawback that a large amount of sand cannot be efficiently cooled.

The present inventors have developed the device described in Japanese Utility Model Publication No. 6-9780 in order to prevent this adverse effect. The sand cooling device described in this publication is shown in FIG. The apparatus shown in this figure includes a chiller 1 for cooling cold water,
The chiller 1 is provided with an agitation cooler 2 for cooling sand with cold water. The agitation cooler 2 includes a cold water tank 3 for storing cold water supplied from the chiller 1, a screw shaft 4 arranged in the cold water tank 3 for transferring sand supplied to the cold water tank 3 while cooling the sand. A motor 5 for rotating the screw shaft 4 is provided.

The screw shaft 4 has spiral fins 6 fixed to the outer periphery of the rotary shaft 4A so that the screw shaft 4 can be rotated to transfer sand. When the motor 5 rotates the screw shaft 4,
The spiral fin 6 transfers sand while cooling the sand in the cold water tank 3.

The sand cooling device having this structure cools the sand in the following steps. The uncooled sand is supplied to the left end of the cold water tank 3 of the stirring and cooling machine 2. Cold water is supplied from the chiller 1 to the cold water tank 3, and the sand supplied to the cold water tank 3 is immersed in cold water. The spiral fin 6 of the screw shaft 4 rotating in the casing transfers sand while stirring. The sand is transferred along the cold water tank 3 while being stirred in cold water and being cooled sufficiently and evenly with cold water. The cooled sand is transferred to the discharge side of the cold water tank 3.

[0013]

The apparatus shown in FIG. 1 can cool sand to about the same temperature as cold water. However, this device has a drawback that the amount of sand cooled per unit time is limited. This is because if the rotation speed of the screw shaft 4 is increased and the amount of sand transferred is increased, the amount of sand mixed in the cold water sucked into the chiller 1 increases. If cold water containing a large amount of sand is sucked into the chiller, the life of the chiller will be significantly shortened. This is because sand has silica as a main component which is also used as an abrasive. When sand passes through the cold water passage of the chiller, it abrades the inner surface of the cold water passage and significantly shortens its life. Further, the cold water mixed with a large amount of sand accumulates locally on the chiller and causes a failure.

Not only the stirrer / cooler having the structure shown in FIG. 1, but the stirrer / cooler for forcibly stirring the sand mixes the circulating cold water with the sand. In particular, as the sand is vigorously stirred to cool the sand efficiently in a short time, a large amount of sand is mixed with the cold water.

The present invention was developed for the purpose of solving this drawback, and the important object of the present invention is to:
By relatively stirring the sand and cold water, the sand can be efficiently cooled in a short time, increasing the processing capacity per unit time,
Moreover, it is another object of the present invention to provide a sand cooling device for use in ready-mixed concrete, which can effectively prevent the harmful effects caused by the sand of the chiller.

[0016]

A sand cooling device used for ready-mixed concrete has all the following configurations. (A) The sand cooling device includes a stirring cooler 2 for immersing the supplied sand in the cold water of the cold water tank 3 to cool it, separating the cooled sand from the cold water, and discharging the sand. Cold water tank 2
Separation tank 8 for precipitating and separating the sand contained in the cold water drained from the chiller, and chiller 1 for sucking the cold water from which the sand has been separated in the separation tank 8 and cooling the sucked cold water to supply it to the cold water tank 3. With. (B) The stirrer / cooler 2 includes a cold water tank 3 for immersing and stirring sand in cold water supplied from the chiller 1, and a screw shaft 4 for transferring sand supplied to the cold water tank 3 while stirring.
And a drainer 14 for discharging the sand transferred by the screw shaft 4 from the cold water tank 3 to the outside. (C) The screw shaft 4 of the stirrer / cooler 2 is a rotary shaft 4A.
The spiral fin 6 is fixed to the outer periphery of the screw shaft 4
When is rotated, the spiral fin 6 is configured to transfer the sand to the drainer 14 while stirring the sand in the cold water tank 3. (D) A sand bypass passage 9 is provided on the separation tank 8 and the discharge side of the agitation cooler 2. (E) The bypass passage 9 is provided with a sand pump 10 for sucking the cold water mixed with sand from the separation tank 8 and a liquid cyclone 11 for separating the sand from the cold water forcibly transferred by the sand pump 10. . (F) The sand discharged from the agitation cooler 2 into the separation tank 8 together with the cold water is retained by the hydrocyclone 11 in the bypass 9
In the above, it is configured to be separated from the cold water and discharged to the discharge side of the stirring and cooling machine 2.

Further, in the sand cooling device according to the second aspect of the present invention, the cooled sand discharged from the agitation cooler 2 and the liquid cyclone 11 is dehydrated by the centrifugal dehydrator 43 to obtain a constant moisture content. And supply it to the fresh concrete mixer.

[0018]

The sand cooling device of the present invention efficiently cools sand in a short time while branching and transferring the sand into two paths. The agitation cooler 2 for forcibly stirring and cooling sand can cool a large amount of sand, but has a property of mixing a large amount of sand with cold water. In particular, the more efficiently a large amount of sand is cooled, there is a drawback that a large amount of sand is mixed with cold water. On the other hand, the liquid cyclone 11 is difficult to cool a large amount of sand like the agitator / cooler 2, but has a characteristic of efficiently separating a small amount of sand contained in a large amount of cold water. The sand cooling device of the present invention comprises a stirring cooler 2 for forcedly stirring and cooling sand, and a liquid cyclone 1.
By effectively utilizing both characteristics of No. 1, the feature of efficiently cooling a large amount of sand in a unit time is realized.

In the apparatus of the present invention, the sand is transferred to the first path and cooled by the agitation cooler 2, and a part of the sand is bypassed to the second path and separated from the cold water by the liquid cyclone 11. This is because it cools. The device according to the invention for separating a part of the sand transferred in the first path from the cold water by bypassing it in the second path is designed to discharge a large amount of sand from the agitation cooler 2 together with the cold water. it can. This is because even if the sand is mixed with cold water and discharged from the agitation cooler 2, it is separated from the cold water by the liquid cyclone 11 in the second path. Therefore, the stirring and cooling machine 2 which is the first route can vigorously stir the sand and efficiently cool it in a short time, and can significantly increase the processing capacity per hour. in spite of,
The sand discharged together with the cold water from the agitation cooler 2 is efficiently separated by the liquid cyclone 11 in the second path and is not circulated in the chiller 1.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a sand cooling device for embodying the technical idea of the present invention, and the present invention does not specify the cooling device to the following.

Further, in this specification, in order to facilitate understanding of the claims, the numbers corresponding to the members shown in the embodiments are referred to as "claims column" and "means for solving the problems.""Column" and "members of action". However, the members shown in the claims are
It is by no means specific to the members of the examples.

The apparatus for cooling ready-mixed concrete sand shown in FIG. 2 is a stir cooler 2 for cooling sand, a separation tank 8 for separating sand mixed with cold water, and a chiller for cooling cold water in the stir cooler 2. 1 and 1. A supply conveyor 13 for supplying sand and a carry-out conveyor 12 for discharging sand are connected to the agitation cooler 2.

Further, in the apparatus shown in the drawing, a sand bypass passage 9 is provided between the separation tank 8 for separating sand from cold water and the carry-out conveyor 12 on the discharge side of the agitation cooling machine 2.
The bypass passage 9 separates the sand discharged from the stirring and cooling machine 2 into the separation tank 8 and supplies the sand to the carry-out conveyor 12. The bypass passage 9 includes a sand pump 10 for sucking cold water mixed with sand from the separation tank 8 and a liquid cyclone 1 for separating sand from the cold water forcibly transferred by the sand pump 10.
1 is provided. Separating tank 8 together with cold water from stirring cooler 2
The sand discharged to (1) is separated from the cold water in the bypass 9 by the liquid cyclone 11 and discharged to the carry-out conveyor 12 connected to the discharge side of the agitation cooler 2.

The stirring and cooling machine 2 is shown in FIGS. The stirring cooler 2 in this figure immerses the sand sent from the supply conveyor 13 in the cold water of the cold water tank 3 to cool it. The agitation cooler 2 includes a cold water tank 3 for storing cold water, a screw shaft 4 disposed in the cold water tank 3, a motor 5 for rotating the screw shaft 4, and sand transferred by the screw shaft 4 in the cold water tank 3 It is provided with a drainer 14 for discharging to the outside.

The cold water tank 3 is composed of a transfer cold water tank 3A having a screw shaft 4 built therein, and a discharge cold water tank 3B connected to the transfer cold water tank 3A and provided with a drainage drainer 14. In the figure, the transfer cold water tank 3A is provided on the left side of the cold water tank 3, and the discharge cold water tank 3B is provided on the right side.

The transfer cold water tank 3A is formed in an elongated gutter shape with an upper opening. The inner surface of the transfer cold water tank 3A is processed into a shape in which a cylinder is cut in half so that the spiral fin 6 can rotate while approaching the inner surface.

The discharged cold water tank 3B supplies the sand sent from the transferred cold water tank 3A to the hopper 15 of the draining / discharging machine 14. The bottom of the discharge cold water tank 3B is designed to be slightly lower than the bottom of the transfer cold water tank 3A. The cold water tank 3 of this shape can smoothly transfer sand from the transfer cold water tank 3A to the discharge cold water tank 3B. Further, as shown in FIG. 3, the bottom of the discharged cold water tank 3B is designed to have a lower center so that the hopper 15 can move closer to it. Cold water is circulated from the chiller 1 to the cold water tank 3.

The screw shaft 4 forcibly stirs and cools the sand supplied to the cold water tank 3, and the spiral fin 6 is fixed to the rotating shaft 4A. The spiral fin 6 has a rotating shaft 4
Radial arm 1 so that a leak gap 7 is created between A and
It is connected to the rotating shaft 4A via 6. Both ends of the rotating shaft 4A are attached to the cold water tank 3 via bearings. The rotating shaft 4A is provided at the center of the transfer cold water tank 3A so as to extend in the longitudinal direction. 3 and 4, the left end of the rotary shaft 4A is connected to the reduction motor 5.

The spiral fin 6 of the screw shaft 4 shown in FIGS. 3 to 5 is made by spirally processing a strip-shaped metal plate. The width of the strip-shaped metal plate is adjusted in the range of several cm to 30 cm. However, the spiral fin 6 does not necessarily have to be in the shape of a band, and a wire having a circular cross section can be used. The spiral fin 6 in which the wire rod is spiral is
It has a low transfer capacity, but has the feature that sand can be stirred more effectively.

The outer shape of the spiral fin 6 wound in a spiral shape is
As shown in FIG. 5, the size is adjusted so as to approach the inner surface of the transfer cold water tank 3A. For example, the spiral fin 6 wound in a spiral shape is designed to have a space of several cm to several tens of cm between the outer peripheral edge and the inner surface of the transfer cold water tank 3A.

The inner diameter of the transfer cold water tank 3A is normally several tens of cmφ.
It is adjusted in the range of up to 300 cmφ. Therefore, the outer diameter of the spiral fin 6 wound in a spiral shape is also several tens of cmφ to 300.
It is adjusted to the range of cmφ. Further, the pitch of the spiral fin 6 is adjusted in the range of several cm to several tens of cm. The spiral fin 6 shown in FIGS. 3 and 4 is formed such that the pitch at the left end is larger than the pitch at the right end. In the screw shaft 4 of this shape, the transfer amount in the left part is larger than the transfer amount in the right part,
It has the feature that a lot of sand accumulates in the right part and is stirred.

The screw shaft 4 transfers the sand supplied to the transfer cold water tank 3A of the cold water tank 3 to the drainer 14. Therefore, the rotation shaft 4A of the screw shaft 4, that is, the spiral fin 6 is arranged so as to extend from the sand supply position toward the drainer / discharging machine 14, and is supplied to the cold water tank 3 by being rotated. The sand thus formed is forcibly stirred and transferred toward the drainer 14. The screw shaft 4 shown in FIGS. 3 and 4 is rotated so as to transfer sand from left to right.

The spiral fin 6 shown in these figures is
It is connected to the rotary shaft 4A via a radial arm 16, and the inner surface of the spiral fin 6 is connected by a rod 18 extending in the axial direction. In this way, by connecting the spiral fins 6 with the rod 18, the spiral fins 6 can be strongly reinforced. It is also possible to stir the sand with the rod 18.

The drainer 14 is arranged on the right side of the cold water tank 3. The drainer 14 drains and removes the incoming sand sent from the transfer cold water tank 3A and transfers it to the next step. The drainer 14 includes a rotating member 19 and a hopper 1.
It consists of five. The rotating member 19 has a central rotating shaft 21 attached to the cold water tank 3 via a bearing so that it can rotate in a vertical plane.

The central rotating shaft 21 is supported in the horizontal plane at right angles to the rotating shaft 4A of the screw shaft 4. The rotary shaft 21 of the water drainage discharger 14 is the rotary shaft 4A of the screw shaft 4.
Is connected via a gear or is rotated by a motor different from the motor that drives the screw shaft 4.

The rotating member 19 has an annular rim 22. The annular rim 22 is connected to the rotating shaft 21 via radial arms 23. The hopper 15 is a rotating member 1.
It is fixed to the outer circumference of the annular rim 22 of No. 9. Hopper 1
No. 5 scoops off the sand accumulated at the bottom of the discharged cold water tank 3B, drains it, and discharges it to the next step.

Therefore, in the hopper 15, a wire mesh or the like is stretched on the bottom, and innumerable water passage holes are opened. The water holes are sized to allow water to pass through but not sand. Rotate the hopper 15 so that it scoops the sand, the opening is on the left side of the rotating member 19 in FIG. 3, and the drained sand is discharged, and the right side of the rotating member 19 is downward in FIG. It is fixed to the member 19. In FIG. 3, an inclined plate 24 that receives the sand discharged from the hopper 15 and sends the sand to the next step is provided on the right side of the draining / discharging machine 14. The annular rim 22 of the rotating member 19 is adjusted to a size such that the hopper 15 moves closer to the bottom of the discharged cold water tank 3B.

Cold water is circulated in the cold water tank 3 in order to cool the sand. Therefore, the cold water supply pipe 25 is connected to the bottom of the cold water tank 3. The cold water supply pipe 25 is connected to the chiller 1. In the cold water tank 3 shown in FIGS. 2 and 3, a cold water supply pipe 25 for supplying cold water is connected to the bottom of the right side portion of the transfer cold water tank 3A, and a cold water drain pipe for discharging cold water from the cold water tank 3 is provided at the left end. 26 are connected. Cold water drain pipe 26
Are connected to the separation tank 8.

The separation tank 8 precipitates and separates the sand contained in the cold water discharged from the cold water tank 3 of the stirring and cooling machine 2. The bottom of the separation tank 8 shown in FIG. 2 is inclined downward toward the center. This is because the sand is efficiently moved to the descending part on the bottom. Further, the separation tank 8 has a partition wall 27 and a supply chamber 28.
And a discharge chamber 29. The partition 27 is provided in the supply chamber 2
The supernatant liquid of No. 8 is allowed to overflow into the discharge chamber 29, and cold water with little sand is caused to flow into the discharge chamber 29. Therefore, the partition wall 27 is arranged below the water surface of the separation tank 8, but is located near the water surface. The separation tank 8 that separates the supply chamber 28 and the discharge chamber 29 by the partition wall 27 effectively prevents the sand from flowing into the discharge chamber 29, and the content of sand contained in the cold water circulated in the chiller 1. Can be reduced.

The discharge chamber 29 is connected to the chiller 1.
The separation tank 8 supplies cold water from which sand has been separated from the discharge chamber 29 to the chiller 1. The cold water is circulated through the stirring cooler 2 → separation tank 8 → chiller 1 → stirring cooler 2. The cold water is cooled by the chiller 1 and circulated to the agitation cooler 2.

The chiller 1 contains a circulation pump and a cooling heat exchanger. The cooling heat exchanger 30 exchanges heat energy between the refrigerant and the cold water to cool the cold water. Cold water contaminated with earth and sand is circulated in the cooling heat exchanger 30 used for this purpose. Therefore, there is a demand for a structure that can easily clean cold water passages soiled with earth and sand.

FIG. 6 shows an example of the cooling heat exchanger. The heat exchanger 30 for cooling of this figure has a cold water pipe 31 which is a cold water channel.
Can be easily cleaned. The cooling heat exchanger 30 includes a plurality of cold water pipes 31 that hermetically penetrate through end plates 33 located at both ends of a cylindrical cold water tank 32, and a communication chamber 17 that connects end portions of the plurality of cold water pipes 31. It has and.

In the cold water tank 32, both ends are hermetically sealed with end plates 33 so that a refrigerant chamber 34 is provided inside so that the refrigerant is vaporized inside and the heat is taken away. As shown in FIG. 2, the refrigerant chamber 34 is connected to the condenser 37 and the compressor 36 via the expansion valve 39.

The entire length of the cold water pipe 31 is formed slightly longer than that of the cold water tank 32, and both ends thereof hermetically penetrate the end plate 33 of the cold water tank 32 and further project from the end plate 33. Cold water pipe 31
Is a hollow pipe made of metal such as iron, titanium alloy or stainless steel.

The ends of the cold water pipe 31 are watertightly connected to the communication chambers 17 at both ends of the cold water tank 32. In the communication chamber 17, a plurality of cold water pipes 31 are connected in series or in parallel, or a plurality of cold water pipes 31 arranged in parallel are connected in series, and a liquid such as cold water is caused to flow through the cold water pipe 31.

Both sides of the communication chamber 17, that is, on the extension line of the cold water pipe 31, are watertightly closed by an opening / closing lid 35 so that the inside of the cold water pipe 31 can be easily cleaned. The opening / closing lid 35 is provided with a flange on the periphery so as to be watertightly sealed. The flange is clamped with a nut. When opening, the nut is removed, the lower part of the nut is lifted and opened, and in this state, a cleaning tool or the like is pushed into the cold water pipe 31 to clean the inside.

As shown in FIG. 2, the cooling heat exchanger 30 is connected to a forced cooling device 20 for supplying a refrigerant thereto. The forced cooler 20 includes a compressor 36, a condenser 37, and a radiator 3 for cooling the condenser 37.
8 and an expansion valve 39. Compressor 36
Sucks the vaporized refrigerant from the cooling heat exchanger 30,
Pressurize and send to condenser 37. Condenser 37
Cools the pressurized refrigerant to liquefy it. Radiator 38
Cools the condenser 37 to liquefy the refrigerant.
As the radiator, a cooling tower or an air-cooled heat exchanger can be used. The expansion valve 39 adjusts the amount of refrigerant supplied to the cooling heat exchanger 30. Cooling heat exchanger 3 through expansion valve 39
The refrigerant sent to 0 is expanded and vaporized in the cooling heat exchanger 30 to remove the heat of vaporization from the surroundings and cool the cold water pipe 31.

The supply chamber 28 of the separation tank 8 has a sand pump 1
0 and a bypass 9 made up of a liquid cyclone 11 are connected. The liquid cyclone 11 separates sand from cold water by utilizing the centrifugal force of cold water. The hydrocyclone 11 is shown in FIGS. 7 and 8. The hydrocyclone 11 in this figure includes a cylindrical casing 11A. The casing 11A has a conical shape with its lower end narrowed down. The sand discharge pipe 40 is connected to the lower end of the casing 11A. The cold water supplied from the supply chamber 28 to the hydrocyclone 11 is forced to flow into the upper part of the casing 11A in a tangential direction. A liquid inflow pipe 41 is tangentially connected to the upper end of the casing 11A.
In order to supply cold water vigorously from the liquid inflow pipe 41 to the casing 11A, the liquid inflow pipe 41 is provided with the sand pump 10
It is connected to the separation tank 8 via. Sand pump 10
Is sucking cold water mixed with sand from the supply chamber 28 of the separation tank 8 and vigorously supplying it to the casing 11A of the liquid cyclone 11. Casing 11 of hydrocyclone 11
At the center of the upper surface of A, a cold water pipe 42 for discharging cold water from which sand has been separated is provided. The cold water pipe 42 is connected to the chiller 1 to supply the chiller 1 with cold water from which sand has been separated.

The liquid cyclone 11 of this structure rotates the cold water supplied from the sand pump 10 inside the casing 11A. The cold water rotating in the casing 11A collects sand around the sand due to the pressure difference. The sand collected in the center flows down by gravity and is discharged from the sand discharge pipe 40 provided at the lower end of the casing 11A. The sand discharged from the sand discharge pipe 40 is supplied to the carry-out conveyor 12 connected to the discharge side of the agitation cooler 2.

The sand discharged from the sand discharge pipe 40 of the hydrocyclone 11 contains cold water. The cold water can be separated from the sand by the carry-out conveyor 12. The carry-out conveyor 12 that separates cold water uses a net material that does not allow sand to pass through the belt but allows cold water to pass through. The cold water contained in the sand discharged from the liquid cyclone 11 can be separated by mounting a drainage container on the belt conveyor. The drainage container used for this purpose comprises a bottom of net material through which cold water does not pass, while sand does not pass. The sand discharged from the liquid cyclone 11 is transferred in a discharge container. The drainage container drains cold water from the bottom and separates it from the sand.

The drainage container is filled with sand discharged from the agitation cooler 2 and transferred, and is further filled with sand into the discharge container,
Sand and cold water can be supplied and transferred from the liquid cyclone 11.

The cooled sand discharged from the agitating cooler 2 and the hydrocyclone 11 is dehydrated by the centrifugal dehydrator 43,
It is supplied to a mixer that mixes green concrete. The centrifugal dehydrator 43 dehydrates the sand having a high water content discharged from the stirring / cooling device 2 and the liquid cyclone 11, and supplies the sand to the mixer for kneading the fresh concrete.

The centrifugal dehydrator 43 is shown in FIG. The centrifugal dehydrator 43 in this figure supplies sand and water to a conical dehydration cylinder 44 that is vibrated in the axial direction while rotating, and dehydrates the water contained in the sand to adjust the moisture content. This centrifugal dehydrator 43 is
The rotating shaft 45 of the spin-drying cylinder 44 prevents the sand from falling under its own weight.
Is horizontal or almost horizontal. Also, the dehydration cylinder 44
The motor 46 that rotates the spinner and the vibration source 47 that vibrates the dehydration cylinder 44 are independent as a non-interlocking structure.
The rotation speed and the vibration state of can be adjusted independently.

The centrifugal dehydrator 43 in this figure supplies sand together with water while the dehydration cylinder 44 is rotating at high speed. In this state, the dehydration cylinder 44 is vibrated in the axial direction. Water is separated from the sand supplied to the dehydration cylinder 44 by centrifugal force and moved in the opening direction of the dehydration cylinder 44. The amount of sand movement can be adjusted by the vibration intensity of the dehydration cylinder 44. Sand with small particles is difficult to separate water. Therefore, the rotation speed of the dehydration cylinder 44 is increased to increase the centrifugal force, or the rotation speed is not changed.
The vibration of the dehydration cylinder 44 is weakened to reduce the moving speed of sand.
On the other hand, since sand with large particles easily separates water, the rotation speed of the dehydration cylinder 44 is slowed down, or vibration is strengthened to increase the sand movement speed without changing the rotation speed. The sand that has been dehydrated and discharged from the dehydration cylinder 44 is collected by the cover 48 and dropped from the discharge port at the lower end.

[0055]

The sand cooling device of the present invention is characterized in that sand can be efficiently cooled in a short time to increase the processing capacity per hour. This is because the sand cooling device of the present invention can stir the sand with the stir-cooler to efficiently cool the sand and to discharge a large amount of sand from the stir-cooler. The sand cooling device of the present invention is a first cooling device that cools sand with a stirring cooler.
The sand is mainly cooled by the route. The first route can be set to a state in which a large amount of sand is discharged together with the cold water, that is, a state in which the sand can be vigorously stirred and efficiently cooled. Therefore, a large amount of sand can be efficiently cooled. The sand discharged together with the cold water from the agitation cooler is separated from the cold water in the bypass path that is the second path. The bypass passage forming the second passage separates sand from cold water by the sand pump and the hydrocyclone. The liquid cyclone cannot separate a large amount of sand from cold water by cooling a large amount of sand like a stirring cooler, but it has an excellent property of separating sand contained in a large amount of cold water. Therefore, the sand cooling device of the present invention effectively utilizes both the characteristics of a stirring and cooling machine that can efficiently cool a large amount of sand by forcibly stirring it, and a liquid cyclone that can efficiently separate the sand from a large amount of cold water, It realizes an extremely important feature of the sand cooling device used for ready-mixed concrete, which is capable of cooling a large amount of sand in a unit time.

In particular, the sand cooling device of the present invention separates sand contained in a large amount of cold water discharged from the agitation cooler by the liquid cyclone. The sand cooler of this structure is
When sand and cold water are agitated by a stirring cooler, the sand and cold water can be separated by a liquid cyclone even if the sand is crushed into small pieces. This is because after the small crushed sand is settled in the separation tank, the settling portion is transferred to the liquid cyclone by the sand pump to separate the sand from the cold water. Therefore, there is a feature that sand and cold water can be vigorously stirred by the stirrer / cooler to be sufficiently cooled.

Further, the sand cooling device used in the ready-mixed concrete of the present invention has a feature that the amount of sand contained in the cold water circulated through the chiller can be extremely reduced, although a large amount of sand can be efficiently cooled. . This is because a large amount of sand is discharged together with cold water from the agitation cooler, but the liquid cyclone provided in the bypass passage separates the sand from the cold water and circulates it in the chiller. The small amount of sand in the chiller that circulates in the chiller reduces the wear of the chiller due to the sand and realizes the feature that chiller failure and maintenance can be simplified.

Further, in the sand cooling device according to the second aspect of the present invention, the sand discharged from the stirring cooler and the liquid cyclone is dehydrated by the centrifugal dehydrator, and the moisture content of the sand is adjusted to be constant and supplied to the fresh concrete. There are features that can be done.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a conventional sand cooling device used for ready-mixed concrete.

FIG. 2 is a schematic sectional view showing a sand cooling device used for ready-mixed concrete according to an embodiment of the present invention.

FIG. 3 is a side view showing an agitating cooler of the cooling device shown in FIG.

FIG. 4 is a plan view of the stirring and cooling machine shown in FIG.

5 is a front view of the stirring and cooling machine shown in FIG.

FIG. 6 is a cross-sectional view showing an example of a cooling heat exchanger used for a chiller.

FIG. 7 is a vertical sectional view of a hydrocyclone used in the device shown in FIG.

FIG. 8 is a horizontal sectional view of a hydrocyclone used in the apparatus shown in FIG.

FIG. 9 is a sectional view showing a centrifugal dehydrator for dehydrating sand.

[Explanation of symbols]

1 ... Chiller 2 ... Stirring cooler 3 ... Cold water tank 3A ... Transfer cold water tank
3B ... Discharge cold water tank 4 ... Screw shaft 4A ... Rotation shaft 5 ... Motor 6 ... Spiral fin 7 ... Leakage gap 8 ... Separation tank 9 ... Bypass passage 10 ... Sand pump 11 ... Liquid cyclone 11A ... Casing 12 ... Delivery conveyor 13 ... Supply Conveyor 14 ... Drainage drainer 15 ... Hopper 16 ... Arm 17 ... Communication chamber 18 ... Rod 19 ... Rotating member 20 ... Forced cooler 21 ... Rotating shaft 22 ... Annular rim 23 ... Arm 24 ... Inclined plate 25 ... Cold water supply pipe 26 ... Cold water drain pipe 27 ... Partition wall 28 ... Supply chamber 29 ... Discharge chamber 30 ... Cooling heat exchanger 31 ... Cold water pipe 32 ... Cold water tank 33 ... End plate 34 ... Refrigerant chamber 35 ... Open / close lid 36 ... Compressor 37 ... Condenser 38 ... Heat dissipation Container 39 ... Expansion valve 40 ... Sand discharge pipe 41 ... Liquid inflow pipe 42 ... Cold water pipe 43 ... Centrifugal dehydrator 44 ... Dehydration cylinder 45 ... Rotation shaft 46 ... Ta 47 ... vibration source 48 ... cover

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000126414 IP Co., Ltd. 485 Yano, Kokufu Town, Tokushima City, Tokushima Prefecture (72) Inventor Minoru Nishio 1 Water resource development public corporation Hinachi Dam Construction at 835 Minami Town, Nabari City, Mie Prefecture In-house (72) Inventor Mitsuya Katayama 1 water resource development public corporation Hinachi dam construction at 835 Minami-cho, Nabari city, Mie prefecture Inside (72) Inventor Kenzo Kinoshita 1 water resource development public corporation Hina at 835 Minami-cho, Nabari city, Mie prefecture Chichi Dam Construction Site (72) Inventor Koichi Shimada 1 Water resource development at 835 Minami-cho, Nabari City, Mie Prefecture Hinachi Dam Construction Site (72) Inventor Heihachi Ito 3870 Kamata, Katanemura, Gunma Prefecture Water Resources Development Public corporation Tokura Dam Construction (72) Inventor Yoshinao Mitsui 4-12-20 Nihonbashihonmachi, Chuo-ku, Tokyo Sato Industry Co., Ltd. (72) Inventor Kim Kazuki 4-12-20 Nihonbashihonmachi, Chuo-ku, Tokyo Sato Industry Co., Ltd. (72) Inventor Kotaro Matsushima 1-1-6 Kitahama, Chuo-ku, Osaka-shi, Osaka Sato Industry Co., Ltd. Osaka Branch (72) Inventor Nakamura Katsumi 1-1-6 Kitahama Chuo-ku, Osaka City, Osaka Prefecture Sato Industrial Co., Ltd. Osaka Branch (72) Inventor Shigeru Nakamura 1-10-10 Nishihonmachi, Nishi-ku, Osaka City Osaka Prefecture Japan National Land Development Co., Ltd. Osaka Branch (72) Inventor Yoshiyuki Shoji 1-10-10 Nishihonmachi, Nishi-ku, Osaka-shi, Osaka Prefecture Japan National Land Development Co., Ltd.Osaka Branch (72) Inventor Ryuzo Yamada 1 450 Inokubo, Shiroji, Ikeda-cho, Miyoshi-gun, Tokushima Prefecture (72) Inventor Masayuki Takeuchi 5-11-522 Sako 4th Town, Tokushima City, Tokushima Prefecture

Claims (2)

[Claims] 1. A sand cooling device for use in ready-mixed concrete, which has all of the following configurations. (A) The sand cooling device is a stirring cooler (2) for immersing the supplied sand in the cold water of the cold water tank (3) to cool it, separating the cooled sand from the cold water and discharging it, and this stirring The separation tank (8) for precipitating and separating the sand contained in the cold water discharged from the cold water tank (3) of the cooler (2) and the cold water separated from the sand in this separation tank (8) are sucked in, A chiller (1) for cooling the sucked cold water and supplying it to the cold water tank (3). (B) The stirrer / cooler (2) comprises a cold water tank (3) for immersing and stirring sand in cold water supplied from the chiller (1), and this cold water tank.
A screw shaft (4) that transfers sand supplied to (3) while stirring it, and sand that is transferred by the screw shaft (4) in a cold water tank (3)
And a drainer (14) for discharging the water from the outside. (C) The screw shaft (4) of the agitation cooler (2) is
The spiral fin (6) is fixed to the outer circumference of (A), and when the screw shaft (4) is rotated, the spiral fin (6) removes sand from the cold water tank (3).
It is configured to transfer to the drainer (14) while stirring inside. (D) A sand bypass passage (9) is provided on the separation tank (8) and on the discharge side of the agitation cooler (2). (E) This bypass passage (9) sucks the sand mixed cold water from the separation tank (8) and the sand pump (10) forcibly transfers the sand from the cold water. And a hydrocyclone (11) for separation. (F) Sand discharged from the agitator / cooler (2) into the separation tank (8) together with the cold water is bypassed by the hydrocyclone (11).
In (9), the water is separated from the cold water and discharged to the discharge side of the agitation cooler (2). 2. A sand cooling device for use in ready-mixed concrete, which has all of the following configurations. (A) The sand cooling device is cooled by immersing the supplied sand in the cold water of the cold water tank (3) to cool it, and separating the cooled sand from the cold water and discharging it, and an agitation cooler (2). Centrifugal dehydrator (43) for dehydrating sand and a separation tank for precipitating and separating the sand contained in the cold water discharged from the cold water tank (3) of the stirring and cooling machine (2)
(8) and the cold water from which sand was separated in this separation tank (8) was inhaled,
Chiller (1) that cools the inhaled cold water and supplies it to the cold water tank (3)
With. (B) The stirrer / cooler (2) comprises a cold water tank (3) for immersing and stirring sand in cold water supplied from the chiller (1), and this cold water tank.
A screw shaft (4) that transfers sand supplied to (3) while stirring it, and sand that is transferred by the screw shaft (4) in a cold water tank (3)
And a drainer (14) for discharging the water from the outside. (C) The screw shaft (4) of the agitation cooler (2) is
The spiral fin (6) is fixed to the outer circumference of (A), and when the screw shaft (4) is rotated, the spiral fin (6) removes sand from the cold water tank (3).
It is configured to transfer to the drainer (14) while stirring inside. (D) A sand bypass passage (9) is provided on the separation tank (8) and on the discharge side of the agitation cooler (2). (E) This bypass passage (9) sucks the sand mixed cold water from the separation tank (8) and the sand pump (10) forcibly transfers the sand from the cold water. And a hydrocyclone (11) for separation. (F) Sand discharged from the agitator / cooler (2) into the separation tank (8) together with the cold water is bypassed by the hydrocyclone (11).
In (9), the cooled sand separated from the cold water and discharged to the discharge side of the stirring cooler (2) and discharged from the stirring cooler (2) and the liquid cyclone (11) is discharged by the centrifugal dehydrator (43). It is designed to be dehydrated.