JPH0534893Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to an apparatus for producing cooled ready-mixed concrete, and in particular, this invention relates to an apparatus that uses a unique belt structure for a conveyor that transports aggregate while cooling it.

[Prior Art and its Problems] It is desirable that the temperature of ready-mixed concrete is low. In particular, the properties of concrete in hot weather, where the daytime temperature exceeds 25°C, are improved by cooling it. Concrete used in hot weather has the disadvantage of low slump, cracks, and reduced strength. The drop in slump is caused by water evaporation. For example, if fresh concrete with a mixing temperature of 30°C and a slump of 18 cm is transported for about an hour using a truck agitator, the slump is said to drop by about 6 cm. When the slump decreases, driving becomes difficult. This fresh concrete needs to be remixed by adding cement paste. Furthermore, even if the amount of water added is adjusted to be the same, the slump of ready-mixed concrete decreases as the temperature increases. Cracks that occur during curing are caused by internal heat generation. The hydration reaction that occurs when concrete hardens is an exothermic reaction. When heat is generated internally, a temperature difference is created between the inside and outside of the concrete. The heated interior expands, and the cooled exterior contracts and cracks. Cracks in concrete are detrimental to all applications. In particular, this is a fatal drawback in the case of dams, piers of bridges installed under the sea, bulkheads of nuclear reactors, etc. Furthermore, the strength of concrete during hot weather decreases when it hardens. These adverse effects can be eliminated by cooling the fresh concrete. As a production device for cooled ready-mixed concrete,
Devices have been developed to cool the added water. However, even if the added water is cooled, the temperature of fresh concrete cannot be lowered that much. The reason is that the amount of water added to fresh concrete is 4 to 6% of the total amount.
The reason is that it is only . Additionally, devices have been developed to cool cement added to fresh concrete. This device blows liquefied nitrogen gas into the cement to forcefully cool it. Although this device has the advantage of being able to cool cement without adding water, it has the disadvantage of extremely high running costs. This is due to the high consumption of expensive liquefied nitrogen gas. For this reason,
This device has the disadvantage that it can only be used with special ready-mixed concrete. Among the materials added to concrete, the material with the highest weight ratio is aggregate. Therefore, cooling the aggregate is effective in lowering the temperature of fresh concrete. To accomplish this, devices have been developed to cool the aggregate. As a device for cooling aggregates, a device has been developed that uses the heat of vaporization of surface water to cool aggregates (Japanese Patent Application Laid-open No. 1983-1999).
−188317). This equipment places aggregates in a sealed tank, evacuates the tank to forcibly evaporate water, and cools the aggregates using the heat of evaporation of the water. This device requires a large pressure tank and a large-capacity vacuum pump, which has the disadvantage of increasing equipment costs. Another disadvantage is that the aggregate cannot be cooled continuously. Furthermore, a device has been developed that cools the aggregate by spraying liquefied nitrogen gas on it (Japanese Patent Laid-Open No. 156045/1983, Japanese Patent Laid-open No. 26407/1999, Japanese Patent Laid-open No. 1-26408).
Publication No.). These devices have the advantage of being able to cool the aggregate without adding water. Another feature is that the aggregate can be cooled to a low temperature. However, similar to the device that cools sand with liquefied nitrogen gas, these devices have the disadvantage of high running costs and can only be used for special purposes. The inventor of the present invention has developed a device for cooling aggregates with cold water in order to solve these conventional drawbacks. This device cools the aggregate by immersing it in cold water. A conveyor is provided to continuously transport and cool the aggregate. The conveyor passes through a cooling water tank, and cold water close to 0°C is circulated in the cooling water tank. This device has the advantage of being able to efficiently cool aggregates. However, there is a drawback that a large amount of aggregate cannot be placed on the conveyor belt and cooled. For this reason,
Processing capacity per hour decreases. The reason why large amounts of aggregate cannot be loaded onto the conveyor belt is because the aggregate is extremely heavy and the conveyor belt cannot withstand its weight. If a large amount of aggregate can be loaded and transported on a conveyor belt, the processing capacity can be increased with a small device. However, when a large amount of aggregate is piled high and transported on a conveyor belt, it becomes difficult to cool all the aggregate evenly. The reason for this is that cold water cannot be circulated sufficiently between the gaps in the aggregate. By providing water permeability by providing countless through holes in the conveyor belt, cold water can flow smoothly between the aggregates. However, having numerous holes in the conveyor belt further reduces its strength. In particular, if many through holes are made to improve water permeability, the strength of the conveyor belt will be significantly reduced. For this reason, the conveyor belt has sufficient strength and
It cannot have water permeability. Further, as the through holes provided in the conveyor belt are used, they become clogged with aggregate and water permeability decreases. For this reason, after a certain period of use, it is necessary to remove aggregates that have clogged the through holes, which requires considerable maintenance. This invention was developed with the aim of resolving this shortcoming.The important purpose of this invention is that the conveyor belt has sufficient strength to transport and efficiently cool a large amount of aggregate. Our goal is to provide chilled ready-mixed concrete production equipment that can. Another important objective of this invention is to provide a chilled ready-mixed concrete manufacturing device that can uniformly cool all the aggregates, and also eliminates clogging of aggregates on the conveyor belt for easy maintenance. There is something to do.

[Means to solve conventional problems]

This device for producing cooled ready-mixed concrete is:
In order to solve the conventional problems, it has the following configuration. (a) The equipment for producing cooled ready-mixed concrete includes a mixer 1, an aggregate cooling water tank 2, and a cooling water tank 2.
, a cooling heat exchanger 4 that cools the cold water supplied to the cooling water tank 2 , a forced cooler 5 that supplies refrigerant to the cooling heat exchanger 4 , and a cooling heat exchanger 5 that supplies refrigerant to the cooling heat exchanger 4 . It is equipped with a circulation pump 6 that circulates cold water between the container 4 and the cooling water tank 2. (b) The conveyor 3 passes through a cooling water tank 2, and the aggregate K to be transported is cooled by the cold water in the cooling water tank 2. (c) The conveyor 3 is a porous conveyor belt 3
A, and a driving means 3B for driving a porous conveyor belt 3A. (d) The porous conveyor belt 3A includes a plurality of hollow pipes 3 arranged parallel to each other at predetermined intervals.
P and a chain 3C to which both ends of the hollow pipe 3P are connected.

[Effect]

The device for producing chilled fresh concrete of this invention cools the aggregate and mixes it with a mixer. Based on FIG. 1 showing a preferred embodiment of this invention,
The operation of this device will be explained. The uncooled aggregate K is supplied to the conveyor 3. The supplied aggregate K is transferred to the cold water of the cooling water tank 2 by the conveyor 3. Conveyor 3
The aggregate K transferred in the cooling water tank 2 comes into contact with cold water and is forcibly cooled. In the cooling water tank 2,
Aggregate K is immersed in cold water and cooled. The cooled aggregate K is sent out by the conveyor 3 and supplied to the mixer 1. Cold water is supplied to the cooling water tank 2 by a circulation pump 6. The cold water is passed through the circulation pump 6 through the cooling water tank 2 → the cold water channel 8 of the cooling heat exchanger 4 → the circulation pump 6
→It is circulated to cooling water tank 2. The circulating cold water is cooled by the cooling heat exchanger 4 and then supplied to the cooling water tank 2 to cool the aggregate K. The refrigerant path 7 of the cooling heat exchanger 4 is supplied with liquefied refrigerant from the forced cooler 5 . The liquefied refrigerant evaporates in the refrigerant path 7 of the cooling heat exchanger 4, and cools the cold water with the heat of evaporation. This device uses a unique porous conveyor belt for the conveyor. A porous conveyor belt consists of a plurality of hollow pipes arranged in parallel and connected at both ends to a chain. A porous conveyor belt with this structure can be made to be lightweight and extremely strong. This is because hollow pipes are extremely resistant to bending. Therefore, a large amount of heavy aggregate can be loaded and transported on the porous conveyor belt, and the cooling capacity can be increased. This is extremely important for this type of device. This is because when constructing large concrete structures, forced cooling of fresh concrete is strongly required. Although large concrete structures generate a large amount of heat internally, they do not radiate much heat from the surrounding area, so they suffer from significant heat-related problems. In addition, large concrete structures
Durability and strength are especially important for dams, bridge piers, etc. Moreover, the device of this invention has the advantage of being able to forcefully cool the entire aggregate evenly, although it has sufficient strength to transport a large amount of aggregate. This is because it uses a porous conveyor belt with hollow pipes arranged in parallel. This structure of porous conveyor belt allows cold water to freely pass between the hollow pipes. Therefore, the cold water that has passed through the porous conveyor belt flows smoothly between the aggregates, and the cold water efficiently cools the entire aggregate in a short time. Furthermore, the device of this invention eliminates aggregate clogging in the gaps in the porous conveyor belt and has the advantage of simplifying maintenance. In a porous conveyor belt with hollow pipes lined up, gaps are created between the hollow pipes, but these gaps become wider toward the opening and continue in the horizontal direction. The gaps in the conveyor belt with this shape are unlikely to be clogged with aggregate, and even if they are clogged, they can be easily removed, so there is no need to unclog the aggregate at regular intervals.

[Preferred embodiment]

Hereinafter, embodiments of this invention will be described based on the drawings. However, the embodiments shown below are illustrative of a device for embodying the technical idea of this invention, and the device of this invention differs from the material, shape, and shape of the component parts.
The structure and arrangement are not limited to those shown below.
Various modifications may be made to the device of this invention within the scope of the claims for utility model registration. Further, in this specification, numbers corresponding to the members shown in the embodiments are added to the members shown in the claims for utility model registration so that the claims for utility model registration can be easily understood. However, the members described in the claims for utility model registration are by no means limited to the members shown in the examples. The apparatus for producing cooled ready-mixed concrete shown in FIG. a conveyor 3 that cools the aggregate K while transferring it; a cooling heat exchanger 4 that cools the cold water in the cooling water tank 2; a forced cooler 5 that supplies refrigerant to the cooling heat exchanger 4; It includes a cooling heat exchanger 4 and a circulation pump 6 that circulates the water to the cooling water tank 2. As the mixer 1, any mixer capable of kneading cooled aggregate, sand, cement, and water can be used. The cooling water tank 2 is shaped like an elongated gutter and is open at the top. The cooling water tank 2 cools the aggregate K by immersing it therein. The size of the cooling water tank 2 is determined by the amount of cooling of the aggregate K per unit time. When the cooling processing amount of aggregate K is 250 tons per hour, the size of the cooling water tank 2 is preferably 2 to 3.5 m in width and 0.6 to 0.6 m in height.
1.5m, and the length can be adjusted to a range of 5 to 15m. The cooling time for aggregate differs depending on its size.
Larger aggregates take longer to cool down than smaller aggregates. Therefore, larger aggregates require longer soaking times in cold water.
By increasing the total length of the cooling water tank 2, the time for immersing the aggregate in cold water can be increased. Therefore, the total length of the cooling water tank 2 for cooling the large aggregate is made long. For example, 5
Cooling water tank 2, which cools 250 tons of aggregate with a diameter of ~150mmφ, has a total length of 10 to 15m and a diameter of 5 to 40mmφ.
The cooling water tank 2 that cools the aggregate has a total length of 5 to 8 m.
shall be. As the cooling water tank 2 is used, dirt accumulates on the bottom. This is because the sediment that adheres to the surface of the aggregate is washed away with cold water and settles to the bottom. Cooling water tank 2
A cleaning port 10 is provided at the bottom of the tank for discharging earth and sand that accumulates on the bottom. The cleaning port 10 is watertightly closed by a detachable plate 11. By removing the removable plate 11, the earth and sand accumulated on the bottom can be discharged. In the cooling water tank 2 of FIG. 1, cold water flows from left to right, and aggregate K is transferred from right to left. That is, the aggregate K is cooled with the supplied cold water and discharged. At the bottom of the cooling water tank 2 is a circulation pipe 9 that supplies cold water.
are connected. A circulation pipe 9 for supplying cold water is connected to the left side of the cooling water tank 2 from which the aggregate K is discharged. On the right side of the connected water tank 2 is a circulation pipe 9 for drainage.
are connected. Inside the cooling water tank 2, a vertical wall 39 is provided between the circulation pipe 9 on the drainage side and the circulation pipe 9 on the supply side. The vertical wall 39 is fixed to the inner surface of the cooling water tank 2 on both sides, and its upper end extends below the porous conveyor belt 3A. By providing the vertical wall 39 in the cooling water tank 2 in this way, the cold water supplied to the cooling water tank 2 can be drained by passing through the porous conveyor belt 3A from bottom to top. Therefore, it has the advantage that the aggregate K can be efficiently cooled with cold water. The circulation pipe 9 on the drainage side is connected to the circulation pump 6 via a filter 12. Filter 12
filters earth and sand contained in the cold water and supplies clear water to the cooling heat exchanger 4. The transport conveyor 3 continuously cools the aggregate K while transporting it. The conveyor 3 transports the aggregate K by placing it on a porous conveyor belt 3A and immersing it in cold water in the cooling water tank 2. In FIG. 2, the porous conveyor belt 3A transports the aggregate K from the right to the left of the cooling water tank 2. The conveyor 3 is a porous conveyor belt 3A.
and a driving means 3B. A porous conveyor belt 3A is shown in FIGS. 3 and 4. The porous conveyor belt 3A shown in this figure is
Belt unit 3 consisting of 4 hollow pipes 3P
U and chain 3 that drives belt unit 3U.
It is composed of C. The interval between the hollow pipes 3P of the belt unit 3U is adjusted to a gap from which the aggregate K does not leak. Therefore, the interval between the hollow pipes 3P is, for example, 1
Adjusted to ~10mm. Both ends of the four hollow pipes 3P are connected to an end plate 3H, and are connected in parallel via the end plate 3H. The hollow pipe 3P connected by the end plate 3H is connected to the chain 3C via a connecting piece 3R fixed to the end plate 3H. The spacing between the hollow pipes 3P connected to the chain 3C is also adjusted to be the same as the spacing between the hollow pipes 3P connected to the end plate 3H. Therefore, the width of the belt unit 3U is made somewhat narrower than the roller spacing of the chain 3C. Vertical partition walls 1 are installed at both ends of the belt unit 3U.
9 is fixed. The partition wall 19 is a hollow pipe 3
To prevent aggregate K carried on P from leaking. The partition wall 19 is made of a plate material strong enough to maintain a vertical posture. The partition wall 19 is fixed to both ends of each belt unit 3U. The partition wall 19 fixed to each belt unit 3U is connected via a flexible bellows 19A so that the porous conveyor belt 3A can be bent. The partition wall and the bellows can be used as separate members connected to each other, but they can also be integrally molded from rubber. Also, as shown in FIGS. 5 and 6, a partition wall that does not use bellows can also be used. This partition wall 19 is
They wrap together to prevent the aggregate K from leaking from between the belt units 3U. The partition wall 19 shown in these figures has an inverted trapezoidal shape in which the upper width is wider than the lower width. The inverted trapezoidal partition walls 19 overlap adjacent partition walls 19 with a predetermined width. As shown in FIG. 5, the wrapping partition walls 19 are connected to the inside and outside so that they can slide relative to each other at the lap portions, with some positional deviation between the inside and outside. Porous conveyor belt 3 with chain 3C
A is driven by a sprocket 15 that rotationally drives the chain 3C, a motor 16 that rotationally drives this sprocket 15, and a chain guide 17. The chain guide 17 is provided on the lower surface of the upper chain 3C on which the aggregate K is placed and transferred.
The chain guide 17 determines the locus of movement of the chain 3C on which the aggregate K is placed. chain 3
C moves the porous conveyor belt 3A on which the aggregate K is placed into the cold water of the cooling water tank 2. Therefore, the chain 3C, as shown in FIG.
The middle part that cools the aggregate K moves at a lower position than both side parts. That is, the upper porous conveyor belt 3A gradually descends from the right sprocket 15, and in the middle, moves horizontally in cold water,
Furthermore, it moves upwardly toward the left sprocket 15. Therefore, in FIG. 2, the chain guide 17 is inclined upwardly on both sides, and is disposed horizontally in the middle. Left sprocket 1 with chain 3C attached
5 is connected to a motor 16 via a speed reducer and is rotationally driven by the motor 16. In this structure, the conveyor 3 transports the aggregate K supplied to the right end of the belt toward the left.
Aggregate K is cooled by immersing it in cold water during transportation.
It is ejected from the left end. The aggregate, which has been immersed in cold water and cooled during the transfer, is preferably drained and fed to the mixer. The aggregate is drained on the discharge side of the conveyor 3, or by connecting a separate draining device between the conveyor 3 and the mixer 1. Draining the aggregate on the discharge side of the conveyor 3 can be achieved by vibrating the belt of the conveyor. In addition, the draining device connected between the conveyor and the mixer includes a device that uses centrifugal force to remove moisture from the aggregate, or a device that removes moisture by placing the aggregate on a net and vibrating it. etc. can be used. The cooling heat exchanger 4 cools the cold water by exchanging thermal energy between the refrigerant and the cold water. Cold water contaminated with earth and sand is circulated through the cooling heat exchanger 4 used for this purpose. Therefore, there is a need for a structure that allows easy cleaning of cold water passages contaminated with earth and sand. Sediment buildup in the cold water passages reduces heat exchange efficiency. FIG. 7, FIG. 8, and FIG. 9 show a cooling heat exchanger 4 that can easily clean a cold water pipe 21, which is a cold waterway. This cooling heat exchanger 4 includes a plurality of cold water pipes 21 that airtightly penetrate end plates 23 at both ends of a cylindrical casing, and a communication chamber that connects the ends of the plurality of cold water pipes 21. . Both ends of the casing 22 are hermetically sealed with end plates 23, and a refrigerant chamber 24 is provided therein so that the refrigerant is vaporized and heat is taken away. Refrigerant chamber 24
A refrigerant inlet 25 and an outlet 26 are opened therein. The inlet 25 is connected to a condenser 28 via an expansion valve 27, and the outlet 26 is connected to the suction side of a compressor 29. The cold water pipe 21 is formed to have a slightly longer overall length than the casing 22, and both ends are connected to the end plate 2 of the casing 22.
3 in an airtight manner and further protrudes from the end plate 23. A hollow iron pipe can be used as the cold water pipe 21.
However, if titanium alloy, stainless steel, or the like is used for the cold water pipe 21, the corrosion resistance will be improved and the durability will be improved. On the outside of the end plate 23, a caulking material having strong adhesion to metal, hardening, cold resistance, and little expansion is attached to the outer periphery of the cold water pipe 21. Furthermore, as shown in FIG. 5, it is also possible to apply caulking material to the entire outer surface of the end plate 23. The cold water pipe 21 is made of a material that can be easily welded to the end plate 23, for example, instead of stainless steel or titanium.
Metal hollow pipes such as iron, copper, brass, aluminum, etc. can also be used. The ends of the cold water pipe 21 are watertightly connected to cold water chambers 30 at both ends of the casing 22 . Cold water chamber 30
In this case, a plurality of cold water pipes 21 are connected in series, in parallel, or several pipes connected in parallel are connected in series, and liquid such as cold water flows through the cold water pipes 21. 8 and 9 show the cold water pipe 2 shown in FIG.
This figure shows the cold water chambers located on the left and right sides of 1, and includes three cold water pipes 21 connected in parallel and partition walls 31 connecting them in series. The partition wall 31 extends to the same plane as the inner surface of the opening/closing lid 32 so as to partition the cold water chamber 30 with the opening/closing lid 32 closed. In this way, partition wall 3
A cooling heat exchanger 4 including a plurality of cold water pipes 2
1 can be connected in series to lengthen the cold water channel. Both sides of the cold water chamber 30, that is, on the extension line of the cold water pipe 21, are provided so that the inside of the cold water pipe 21 can be easily cleaned.
It is watertightly closed with an opening/closing lid 32. Opening/closing lid 32
As shown in FIG. 7, the upper edge is attached to the upper edge of the cold water chamber 30 via a hinge 33. A flange 34 is provided around the opening/closing lid 32 so that the cold water chamber 30 can be sealed watertightly. The flange 34 is clamped with a nut 35. When opening, remove the nut 35, lift the lower part of the nut 35 to open it, and in this state, push a cleaning tool or the like into the cold water pipe 21 to clean the inside. The cold water chamber 30 has a cold water inlet 36 and a cold water outlet 3.
7 is open. The forced cooler 5 that supplies refrigerant to the cooling heat exchanger 4 includes a compressor 29 and a condenser 2.
8, and a radiator 38 that cools the condenser 28.
and an expansion valve 27. The compressor 29 sucks vaporized refrigerant from the cooling heat exchanger 4, pressurizes it, and sends it to the condenser 28. The condenser 28 cools and liquefies the pressurized refrigerant. The heat sink 38 cools the condenser 28 and
Liquefies the refrigerant. A cooling tower air-cooled heat exchanger can be used as a radiator. The expansion valve 27 adjusts the amount of refrigerant supplied to the cooling heat exchanger 4. The refrigerant sent to the cooling heat exchanger 4 through the expansion valve 27 is expanded and vaporized in the cooling heat exchanger 4, absorbs vaporization heat from the surroundings, and cools the cold water pipe 21. The circulation pump 6 supplies the cold water cooled by the cooling heat exchanger 4 to the cooling water tank 2 to cool the aggregate K.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of a chilled ready-mixed concrete manufacturing apparatus showing an embodiment of this invention, Figure 2 is a cross-sectional view showing an example of a cooling water tank, and Figures 3 to 6 are porous conveyor belts. FIG. 7 is a sectional view showing an example of a cooling heat exchanger, and FIGS. 8 and 9 are sectional views showing an end portion of the cooling heat exchanger. 1...Mixer, 2...Cooling water tank, 3...Transport conveyor, 3A...Porous conveyor belt, 3B
... Drive means, 3C ... Chain, 3U ... Belt unit, 3P ... Hollow pipe, 3H ... End plate, 3R ... Connection piece, 4 ... Cooling heat exchanger, 5
... Forced cooler, 6 ... Circulation pump, 7 ... Refrigerant path, 8 ... Cold water channel, 9 ... Circulation pipe, 10 ... Cleaning port, 11 ... Detachment plate, 12 ... Filter, 15
...Sprocket, 16...Motor, 17...
Chain guide, 19... Bulkhead, 19A... Bellows, 21... Cold water pipe, 22... Casing, 23
... End plate, 24 ... Refrigerant chamber, 25 ... Inflow port, 2
6... Discharge port, 27... Expansion valve, 28... Condenser, 29... Compressor, 30... Cold water chamber, 31... Partition wall, 32... Opening/closing lid, 33...
Hinge, 34...Flange, 35...Nut, 36
...Inlet, 37...Outlet, 38...Radiator,
39... Vertical wall, K... Aggregate.

Claims (1)

[Claims for Utility Model Registration] Mixer 1, aggregate cooling water tank 2, conveyor 3 provided in cooling water tank 2, and cooling heat exchanger 4 for cooling cold water supplied to cooling water tank 2.
, a forced cooler 5 that supplies refrigerant to the cooling heat exchanger 4, and a circulation pump 6 that circulates cold water between the cooling heat exchanger 4 and the cooling water tank 2, and the conveyor 3 is connected to the cooling water tank 2. In the apparatus for producing ready-mixed concrete, which is configured to cool the aggregate K during transport, the transport conveyor 3 is connected to the porous conveyor belt 3A.
and a driving means 3B for driving the porous conveyor belt 3A.
A is a cooled ready-mixed concrete system characterized by being composed of a plurality of hollow pipes 3P arranged parallel to each other at predetermined intervals, and a chain 3C to which both ends of the hollow pipes 3P are connected. Manufacturing equipment.