Method of heating aggregate for concrete and heating system used therefor

Abstract

To reduce the loss of energy by improving energy efficiency, to reduce a load in the maintenance and renewal of equipment by simplifying the equipment in a concrete manufacturing factory, to stabilize the fresh properties of concrete by easily grasping the moisture content of aggregate and to reduce an environmental load in a method and a system for heating the aggregate for concrete.SOLUTION: In this method and this system, an electric furnace oxidized slag aggregate A is adopted as an aggregate for concrete, and the aggregate A is directly heated by irradiating the aggregate A with microwaves by a microwave generator M in a process of feeding the aggregate A to a concrete manufacturing facility.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for heating aggregate for concrete and a heating system used therefor. [Background technology]

[0002] In general, in concrete manufacturing plants, concrete materials are sequentially removed from multiple material silos and supplied to multiple material storage bins installed above a batcher plant. Each material is then weighed and mixed from these storage bins to produce concrete. In this case, a conveyor such as a belt conveyor is used to supply aggregate to the material silos. A belt conveyor is installed horizontally below the material silo that stores the aggregate, and another belt conveyor is installed diagonally between this belt conveyor and the material storage bins above the batcher plant. The aggregate is transported to the material storage bins by these belt conveyors (see Patent Document 1).

[0003] It is also known that in concrete production, the hardening of concrete can be accelerated by heating the concrete materials while mixing them (hot mixing) and pouring the concrete at 50°C-80°C into a formwork (see Patent Documents 2 and 3).

[0004] This type of hot mixing involves using warm water as mixing water for the concrete materials, injecting high-temperature steam into a mixer when mixing the concrete materials, and heating materials such as aggregates.Among these, a common method of heating aggregate involves filling a cover with heated steam in an aggregate silo or on a cylindrical covered conveyor that transports aggregate from the aggregate silo to the material storage bins of a batcher plant, and indirectly heating the aggregate with this heated steam (see Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 57-38495 [Patent Document 2] Japanese Patent Application Publication No. 51-57708 [Patent Document 3] Japanese Patent Application Publication No. 51-86517 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the method of heating aggregate with steam is used for hot mixing of concrete, the following problems arise. (1) This method does not directly heat the aggregate, resulting in poor energy efficiency and increased running costs. (2) In particular, in the method of heating aggregates with heated steam on a covered conveyor, the cover is not airtight, so there is a large loss of energy in filling the space inside the cover with heated steam, and running costs increase. (3) In order to stabilize the fresh properties of concrete, it is necessary to grasp the moisture content of the aggregate. However, using steam makes it difficult to control the moisture content of the aggregate. (4) Steam is supplied to concrete manufacturing plants using equipment such as boilers and piping, which is installed within the plant. However, the piping within the plant is complex, and maintaining and updating this equipment places a heavy burden on the plant.

[0007] The present invention solves these conventional problems, and aims to improve energy efficiency and reduce energy loss in this type of heating method for concrete aggregate and the heating system used therein, thereby reducing running costs, simplify the equipment (heating equipment) within concrete manufacturing plants, thereby reducing the burden of maintaining and updating the equipment, make it easier to grasp the moisture content of the aggregate, stabilize the fresh properties of concrete, and also reduce the environmental burden. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides: 1. A method for heating concrete aggregate, comprising heating concrete aggregate contained in concrete material by a heating device during a process of feeding the concrete material to a concrete manufacturing facility, the method comprising: The concrete aggregate is made of electric furnace oxidized slag, A microwave generator is used as the heating device, In the process of feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing facility, the electric furnace oxidizing slag aggregate is directly heated by irradiating the electric furnace oxidizing slag aggregate with microwaves from the microwave generator. The gist of this is as follows.

[0009] The method for heating the aggregate for concrete is embodied as follows. (1) A shielded area for preventing microwave leakage is defined on the path along which electric furnace oxidizing slag aggregate is fed to a concrete manufacturing facility, and a microwave generator is installed in the shielded area. (2) The feed path for feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing equipment is composed of a conveyor for transporting the electric furnace oxidizing slag aggregate and a hollow cylindrical cover surrounding the conveyor, and the cover is made of a metal material capable of blocking microwaves, thereby defining a shielded area on the feed path. (3) Instead of the above (2), the feeding path for feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing equipment may be configured by a conveyor for transporting the electric furnace oxidizing slag aggregate and a hollow cylindrical cover surrounding the conveyor, and a hollow cylindrical shielding cover made of a metal material capable of blocking microwaves may be placed inside the cover to define a shielding area on the feeding path.

[0010] In order to achieve the above object, the present invention provides: A heating system used in the above method for heating concrete aggregate, a shielding facility disposed on a feed path for feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing facility, the shielding facility preventing microwave leakage; a microwave generator installed in the shielding equipment for irradiating microwaves toward the electric furnace oxidizing slag aggregate; It consists of The gist of this is as follows. [Effects of the Invention]

[0011] According to the method and system for heating concrete aggregate of the present invention, electric furnace oxidizing slag aggregate is used as the concrete aggregate, and during the process of transporting the electric furnace oxidizing slag aggregate to a concrete manufacturing facility, the electric furnace oxidizing slag aggregate is directly heated by irradiating it with microwaves from a microwave generator, thereby achieving the following unique and exceptional effects of the present invention. (1) By directly heating the electric furnace oxidizing slag aggregate by irradiating it with microwaves, it is possible to improve energy efficiency and reduce energy loss, thereby reducing running costs. (2) Since it is only necessary to define a shielded area (shielding equipment) on the feed path of the electric furnace oxidized slag aggregate and install a microwave generator therein, the equipment within the concrete manufacturing plant can be simplified, and the burden on equipment maintenance and renewal can also be reduced. (3) By directly heating electric furnace oxidizing slag aggregate by irradiating it with microwaves, it becomes easier to determine the moisture content of the aggregate, which makes it possible to stabilize the fresh properties of concrete. (4) By using electric arc furnace oxidizing slag aggregate as concrete aggregate, a physical phenomenon called ferromagnetic resonance occurs in the electric arc furnace oxidizing slag aggregate when microwaves are irradiated, causing the electric arc furnace oxidizing slag aggregate itself to generate heat. This heat generation effect can also heat the aggregate, improving energy efficiency. In this case, using environmentally friendly electric arc furnace oxidizing slag aggregate can also reduce the environmental impact. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view showing an image of a method and a system for heating aggregate for concrete according to a first embodiment of the present invention; [Figure 2] FIG. 10 is a side view showing the configuration of the heating method and heating system. [Figure 3] 1 is a side view showing a configuration of a method and a system for heating aggregate for concrete according to a second embodiment of the present invention; [Figure 4] A diagram showing an image of the application of this heating method and heating system to a typical concrete manufacturing plant. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, embodiments of the present invention will be described with reference to the drawings. Figures 1 and 2 show a first embodiment.

[0014] As shown in Figure 1, this method for heating concrete aggregate (hereinafter referred to as this method) involves heating the concrete aggregate contained in the concrete material using a heating device during the process of transporting the concrete material to a concrete manufacturing facility. In this method, aggregate that can be heated by microwave irradiation is used as the aggregate for concrete, a microwave generator is used as the heating device, and the aggregate is heated by irradiating it with microwaves from the microwave generator during the process of transporting the aggregate to a concrete manufacturing facility.

[0015] As shown in Figure 2, this method uses electric arc furnace oxidizing slag aggregate (hereinafter referred to as electric arc furnace oxidizing slag aggregate A or simply aggregate A), which is a type of aggregate that has surface water and is magnetic, as aggregate A that can be heated by microwave irradiation. Electric arc furnace oxidizing slag aggregate A is made by specially processing oxidizing slag generated in electric arc furnace steelworks from a molten state at approximately 1500°C, crushing and classifying it into coarse and fine aggregates. It can be used as a substitute for natural materials such as natural sand (sea sand, mountain sand), natural gravel, crushed sand, and crushed stone. This electric arc furnace oxidizing slag aggregate A is magnetic and has the ability to absorb radio waves (microwaves) and convert them into heat. This method also utilizes these properties of electric arc furnace oxidizing slag aggregate A. Electric furnace oxidized slag aggregate A contributes to the protection of the natural environment, the reduction of fossil fuels through aggregate transportation and heavy concrete construction, and CO 2 Its reduction effects have been recognized, and it was designated as a specific procurement item in 2005, and it has been standardized in JIS A 5011-4 "Slag aggregate for concrete - Part 4: Electric arc furnace oxidizing slag aggregate." Furthermore, due to the current situation of banning the extraction of natural aggregate, restrictions on resource development, and aggregate depletion, this electric arc furnace oxidizing slag aggregate A is attracting attention as an environmentally friendly aggregate, and there is a movement to standardize it at ready-mix concrete plants in Japan.

[0016] In this method, a shield area S is defined on the path along which the aggregate A is fed to the concrete manufacturing facility to prevent leakage of microwaves, and a microwave generator M is installed within this shield area S.

[0017] In this case, the supply path for electric furnace oxidizing slag aggregate A to the concrete manufacturing facility is composed of a conveyor B that transports the aggregate A and a hollow cylindrical cover C that surrounds the conveyor B. Here, a belt conveyor (hereinafter referred to as belt conveyor B) is used as the conveyor B, and multiple belt conveyors B are connected in the longitudinal direction. The cover C is an arch-shaped cover made of metal, and multiple covers C are placed on each belt conveyor B. In this way, the supply path for aggregate A is formed in a tunnel shape by multiple belt conveyors B and covers C. Note that instead of an arch-shaped cover, a cylindrical metal pipe may be used for the cover C, and multiple metal pipes may be connected to form a tunnel shape. In this case, the belt conveyor B is inserted into this metal pipe. A shielded area S is defined in part of the supply path for aggregate A to prevent microwave leakage. Here, the shielded area S is formed by forming a part of the cover C from a metal material such as steel that can block microwaves as a shield cover C1, and by installing a shield cover C2 made of a metal material such as steel that can block microwaves as a partition at both ends of the internal space surrounded by this shield cover C1, i.e., at one end where the aggregate A enters the internal space and the other end where it exits the internal space, so that the aggregate A can pass through. In this way, a part of the feed path of the aggregate A is partitioned by the shield covers C1 and C2 to form the shielded area S. Note that here, a part of the cover C is formed from a steel material or the like as the shield cover C1, but the entire cover C may be formed from a steel pipe or the like and the entire cover C may be formed as the shield cover C1.

[0018] In this case, the microwave generator M is selected from various industrial microwave generators that use specific frequencies. The microwave generator M is installed at a predetermined height within the shielded area S on the feed path of the electric furnace oxidizing slag aggregate A, with the microwave radiation direction facing the belt conveyor B.

[0019] As the electric arc furnace oxidizing slag aggregate A used as aggregate A is transported to the concrete production facility via a belt conveyor B, a microwave generator M irradiates the electric arc furnace oxidizing slag aggregate A with a predetermined intensity for a predetermined duration in a shielded area S installed along the transport path. When microwaves are irradiated onto the electric arc furnace oxidizing slag aggregate A in the shielded area S while the aggregate A contains water on its surface, the microwaves are absorbed by the aggregate A, causing it to generate heat. This heat generation directly heats the aggregate A, raising its surface temperature to a predetermined temperature. Furthermore, the magnetic electric arc furnace oxidizing slag aggregate A undergoes a physical phenomenon known as ferromagnetic resonance, which ultimately increases the internal energy of the electric arc furnace oxidizing slag aggregate A, ultimately generating heat. This directly heats the aggregate A. Thus, the electric arc furnace oxidizing slag aggregate A is heated to the predetermined temperature by its own heat generation and is then transported to the concrete production facility.

[0020] As explained above, according to this method, an electric furnace oxidizing slag aggregate A, which contains surface water and has magnetic properties, is used as an aggregate that can be heated by microwave irradiation. During the process of transporting this electric furnace oxidizing slag aggregate A to the concrete manufacturing equipment, microwaves are irradiated by a microwave generator M to directly heat this aggregate A, thereby improving energy efficiency and reducing energy loss, thereby reducing running costs.

[0021] Furthermore, according to this method, the feeding route for feeding this aggregate A to the concrete manufacturing equipment is formed by a belt conveyor B and a cover C, a shielded area S is formed on part of this feeding route by shield covers C1 and C2, and a microwave generator M is installed within this shielded area S, thereby providing heating equipment, which can be easily installed within a concrete manufacturing plant. Furthermore, this heating equipment does not require the complicated piping required for conventional steam-heated equipment, which simplifies the heating equipment within the concrete manufacturing plant and reduces the burden of maintaining and updating the heating equipment.

[0022] Furthermore, according to this method, the moisture content of the electric furnace oxidizing slag aggregate A can be easily determined by determining the microwave irradiation intensity and irradiation time, etc., of the electric furnace oxidizing slag aggregate A and the moisture content of the aggregate A through preliminary experiments before implementation at the concrete manufacturing plant. This makes it easier to determine the moisture content of the aggregate A and stabilizes the fresh properties of the concrete.

[0023] Furthermore, this method uses electric arc furnace oxidizing slag aggregate A containing surface water, and by irradiating this aggregate A with microwaves, a physical phenomenon called ferromagnetic resonance occurs in the aggregate A, causing the aggregate A to generate heat itself, and this heat generation effect is also utilized to directly heat the aggregate A, thereby further improving energy efficiency. In this case, using environmentally friendly electric arc furnace oxidizing slag aggregate A also helps reduce the environmental impact.

[0024] The heating system used in this method (hereinafter referred to as the present system) is also shown in Figures 1 and 2. The present system is composed of a shielding device F, which is located on the path along which electric furnace oxidizing slag aggregate A containing surface water is fed to the concrete manufacturing equipment and prevents microwave leakage, and a microwave generator M, which is installed inside the shielding device F and irradiates microwaves toward the electric furnace oxidizing slag aggregate A.

[0025] In this system, the feeding path for feeding electric furnace oxidizing slag aggregate A to the concrete manufacturing equipment is composed of a conveyor B for transporting the aggregate A and a hollow cylindrical cover C surrounding the conveyor B. At least a part of the cover C is made of a metal material that can block microwaves and serves as a shielding equipment F.

[0026] In this case, the conveyor B is a general belt conveyor (hereinafter referred to as belt conveyor B), and is composed of a conveyor frame b1, a plurality of conveyor rollers b2 supported so as to be rotatable in the vertical direction via shafts arranged horizontally at both ends of the conveyor frame b1 and between the ends, an endless conveyor belt b3 wound around each of the conveyor rollers b2 so as to be rotatable in the vertical direction, and a drive device (not shown) that drives some of the plurality of conveyor rollers b2 as drive rollers D and rotates the conveyor belt b3. The drive device is controlled by a control panel (not shown). Under the control of this control panel, the drive roller D is driven or stopped at a predetermined speed, and the conveyor belt b3 is rotated or stopped, so that the electric furnace oxidizing slag aggregate A on this conveyor belt b3 is irradiated with microwaves of a predetermined irradiation intensity for a predetermined irradiation time. Also, under the control of this control panel, the drive roller D can be rotated in the forward and reverse directions, and by reciprocating the conveyor belt b3, the electric furnace oxidizing slag aggregate A can be irradiated with microwaves for a predetermined irradiation time.

[0027] The covers C are arch-shaped covers made of metal material, and multiple covers C are placed on each belt conveyor B. In this way, a tunnel-shaped feed path for the electric furnace oxidizing slag aggregate A is formed by multiple belt conveyors B and the arch-shaped covers C. Note that instead of arch-shaped covers, cylindrical metal pipes may be used for the covers C, and multiple metal pipes may be connected in the longitudinal direction to form a tunnel. In this case, the belt conveyor B is inserted into these metal pipes.

[0028] A shielding system F for preventing microwave leakage is defined in a portion of the feed path of the aggregate A. In this shielding system F, some of the covers C are formed by shield covers C1 made of a metal material, such as steel or iron plate, capable of blocking microwaves. At both ends of the internal space surrounded by the shield cover C1, i.e., at one end where the aggregate A enters the internal space and at the other end where it exits the internal space, shield covers C2 made of a metal material, such as steel or iron plate, capable of blocking microwaves are installed as partitions, so that the aggregate A can pass through. Thus, the shielding system F is formed by the shield covers C1 and C2 in a portion of the feed path of the electric furnace oxidizing slag aggregate A. Note that, in this example, only a portion of the cover C is designated as the shield cover C1. However, the entire cover C may be made of a steel pipe or the like, and the entire cover C may be the shield cover C1. Furthermore, each partitioning shield cover C2 may be openable and closable to increase the airtightness of the internal space.

[0029] In this case, the microwave generator M is selected from various industrial microwave generators that use specific frequencies, as described above. The microwave generator M is placed at a predetermined height within the shielding equipment F on the feeding path of the electric furnace oxidizing slag aggregate A, with the microwave radiation direction facing the belt conveyor B.

[0030] In this way, the electric furnace oxidizing slag aggregate A containing surface water is transported to the concrete manufacturing equipment by the belt conveyor B. During this process, the electric furnace oxidizing slag aggregate A is irradiated with microwaves generated by the microwave generator M at a predetermined irradiation intensity for a predetermined irradiation time by the shielding equipment F installed in part of this transport route.

[0031] Thus, by irradiating the electric arc furnace oxidizing slag aggregate A on the belt conveyor B with microwaves at a predetermined intensity for a predetermined duration while the aggregate A has surface water, the aggregate A absorbs the microwaves and directly heats the aggregate A through its own heat generation. This raises the surface temperature of the aggregate A to a predetermined temperature. At the same time, the magnetic electric arc furnace oxidizing slag aggregate A exhibits a physical phenomenon called ferromagnetic resonance. That is, by irradiating the magnetic electric arc furnace oxidizing slag aggregate A with microwaves, dynamic electron spin motion is generated in the electric arc furnace oxidizing slag aggregate A, causing ferromagnetic resonance, which increases the internal energy of the electric arc furnace oxidizing slag aggregate A. Under this ferromagnetic resonance, microwave energy is efficiently absorbed by the electric arc furnace oxidizing slag aggregate A, continuously inducing dynamic electron spin motion, and significantly increasing the internal energy of the electric arc furnace oxidizing slag aggregate A. The internal energy of the electric arc furnace oxidizing slag aggregate A, which increases due to this ferromagnetic resonance, is converted into heat, and ultimately the electric arc furnace oxidizing slag aggregate A itself generates heat. This heat generation directly heats the electric furnace oxidizing slag aggregate A. This raises the temperature of the aggregate A to the desired level. In this way, the electric furnace oxidizing slag aggregate A is heated to the desired temperature by its own heat generation and is then supplied to the concrete manufacturing facility.

[0032] As explained above, this system uses magnetic electric furnace oxidizing slag aggregate A, which contains surface water. During the process of transporting this electric furnace oxidizing slag aggregate A to the concrete manufacturing equipment, microwaves are irradiated by a microwave generator M to directly heat this aggregate A. This improves energy efficiency, reduces energy loss, and reduces running costs.

[0033] In addition, according to this system, the feeding route for feeding this electric furnace oxidized slag aggregate A to the concrete manufacturing equipment is formed by a belt conveyor B and a cover C, and a shielding equipment F is formed in part of this feeding route using shielding covers C1 and C2, and a microwave generator M is installed inside this shielding equipment F to provide heating equipment.Therefore, there is no need for complex piping like in conventional steam heating equipment, and the heating equipment within the concrete manufacturing plant can be simplified, and the burden on equipment maintenance and renewal can be reduced.

[0034] Furthermore, with this system, before implementing this system in a concrete manufacturing plant, experiments can be conducted in advance using this system or a simulation system to determine the microwave irradiation intensity and irradiation time of electric furnace oxidizing slag aggregate A and the moisture content of this aggregate A, making it possible to grasp the moisture content of this aggregate A when heated by microwaves. Therefore, with this system, it is easy to grasp the moisture content of aggregate A, and the fresh properties of concrete can be stabilized.

[0035] Furthermore, this system uses electric arc furnace oxidizing slag aggregate A containing surface water, and by irradiating this aggregate A with microwaves, a physical phenomenon called ferromagnetic resonance occurs in aggregate A, causing the aggregate A itself to heat up. This heat generation effect is also utilized to directly heat aggregate A, thereby further improving energy efficiency. In this case, environmentally friendly electric arc furnace oxidizing slag aggregate A is used, which also helps to reduce the environmental impact.

[0036] FIG. 3 shows a second embodiment of the method and system. This embodiment is similar to the first embodiment in that the method uses electric arc furnace oxidizing slag aggregate A containing surface water, and the feed path for feeding the electric arc furnace oxidizing slag aggregate A to the concrete production facility is composed of a conveyor B for transporting the aggregate A and a hollow cylindrical cover C surrounding the conveyor B. However, this embodiment differs from the first embodiment in that the cover C is not made of a metal material capable of blocking microwaves, thereby defining a shielded area S on the feed path. Furthermore, this system is similar to the first embodiment in that the feed path for feeding the electric arc furnace oxidizing slag aggregate A to the concrete production facility is composed of a conveyor B for transporting the aggregate A and a hollow cylindrical cover C surrounding the conveyor B. However, this embodiment differs from the first embodiment in that the cover C is not made of a metal material capable of blocking microwaves, which serves as a shielding device F. In this embodiment, the same symbols as in the first embodiment are used for the components that are common to the first embodiment, and duplicate explanations are omitted, and only the components that are different from the first embodiment are used with new symbols and explanations are added.

[0037] As shown in Figure 3, in this method, the feeding path for feeding electric furnace oxidizing slag aggregate A to a concrete manufacturing facility is composed of a conveyor B for transporting this aggregate A and a hollow cylindrical cover C surrounding the conveyor B. Then, a hollow cylindrical shielding cover C3 made of a metal material capable of blocking microwaves is placed inside the cover C to define a shielding area S on the feeding path for the aggregate A.

[0038] In this case, the shield cover C3 is made of a metal material such as a steel pipe capable of blocking microwaves and is formed into a cylindrical or rectangular tube shape with a predetermined diameter and a predetermined length shorter than the axial length of the cover C, forming a tunnel-like shape overall, so that it can be incorporated into the cover C as a whole. The length of this shield cover C3 is determined based on the microwave irradiation intensity and irradiation time to the aggregate A on the belt conveyor B. Then, this shield cover C3 is incorporated into and installed at a predetermined position within the cover C, and the belt conveyor B passes through this shield cover C at this installed position.

[0039] In this method, the system has a feed path for feeding electric furnace oxidizing slag aggregate A to a concrete manufacturing facility, which path is composed of a conveyor B for transporting the aggregate A and a hollow cylindrical cover C surrounding the conveyor B. Inside the cover C, a hollow cylindrical shield cover C3 made of a metal material capable of blocking microwaves is placed as a shielding facility F.

[0040] In this case, the shield cover C3 is composed of an outer periphery C31 made of a metal material such as a steel pipe or an iron pipe that can block microwaves, and end portions C32 that shield both ends of the outer periphery C31 and are made of a metal material such as a steel plate or an iron plate that can block microwaves. Note that each end portion C32 may be openable / closable so as to open and close the internal space of the outer periphery C31.

[0041] The microwave generator M is disposed at a predetermined height within the shield cover C3, and is installed so that the microwave irradiation direction is directed onto the belt conveyor B, as in the first embodiment.

[0042] Even if the present method and system are configured in this way, the same effects as those of the first embodiment can be achieved.

[0043] Figure 4 shows an example of application of this method and system in a typical concrete manufacturing plant. As shown in Figure 4, in this concrete manufacturing plant, cement is supplied from cement silo P1 and aggregates are supplied from aggregate silo P2 to multiple material storage bins BP1 above batcher plant BP. Then, in the batcher plant BP, cement and each aggregate are weighed in weighing bins BP2 from material storage bin BP1 and dropped into mixer BP3. There, they are mixed with water supplied from water supply system P3 and admixtures supplied from admixture system P4 to produce concrete. This concrete is discharged from mixer BP3 through hopper BP4. In this type of concrete manufacturing plant, aggregates from aggregate silo P2 are transported to the batcher plant BP by belt conveyor B. In this case, the aggregates in the aggregate silo P2 are removed onto a belt conveyor B1 installed horizontally below the aggregate silo P2, and then transferred to a belt conveyor B2 installed diagonally between this belt conveyor B1 and the material storage bin BP1 above the batcher plant BP, and the aggregates are transported to the material storage bin BP1 by this belt conveyor B2.

[0044] As shown in Figure 4, the present method and system are implemented in this concrete manufacturing plant using a conveyor B that transports aggregate. In this concrete manufacturing plant, a cover C made of multiple metal pipes is installed between a belt conveyor B1 installed in an aggregate silo P1 and a material storage bin BP1 above a batcher plant BP, with the cover C supported in the middle by a support column CP, and a belt conveyor B2 is inserted into this cover C. The present method and system are realized by forming a shielded area S (shielding equipment F) on part of this cover C using shield covers C1 and C2, and installing a microwave generator M (see Figures 2 and 3) within this shielded area S (shielding equipment F) to incorporate microwave heating equipment. The shielded area S (shielding equipment F) and microwave generator M have been described above.

[0045] In this concrete manufacturing plant, electric arc furnace oxidizing slag aggregate A stored in aggregate silo P2 is transported via belt conveyor B2 inside cover C to material storage bin BP1 above batcher plant BP. In the process, microwaves are irradiated onto the aggregate A by microwave generator M at a predetermined intensity and for a predetermined duration in shielded area S (shielding equipment F) installed in part of cover C. As described above, the microwaves are absorbed by electric arc furnace oxidizing slag aggregate A, which contains surface water, and the aggregate A is directly heated by its own heat generation. At the same time, ferromagnetic resonance occurs in the magnetic electric arc furnace oxidizing slag aggregate A, directly heating the aggregate A by its own heat generation. Thus, the aggregate A is heated to the predetermined temperature.

[0046] By doing so, even in a general concrete manufacturing plant, the above-described operational effects based on this method and this system can be achieved.

[0047] This method can be implemented by utilizing existing equipment in a concrete manufacturing plant, consisting of a belt conveyor B surrounded by a cover C that transports aggregate from an aggregate silo P2 to a material storage bin BP1 in a batcher plant BP. Similarly, this system can be realized by simply forming a shielding facility F using shield covers C1 and C2 on part of an existing facility in a concrete manufacturing plant, consisting of a belt conveyor B surrounded by a cover C that transports aggregate from an aggregate silo P2 to a material storage bin BP1 in a batcher plant BP, and installing a microwave generator M inside this shielding facility F.

[0048] In the above embodiments, electric furnace oxidizing slag aggregate A, which has surface water and is magnetic, is used as the aggregate that can be heated by microwave irradiation. However, the aggregate that can be heated by microwave irradiation can be selected arbitrarily from aggregate that has surface water, magnetic aggregate that includes electric furnace oxidizing slag aggregate, and magnetic aggregate that includes surface water. By using aggregate that can be heated by microwave irradiation as the aggregate for concrete, it is possible to achieve the same effects as those of the above-described embodiments.

[0049] Furthermore, in each of the above embodiments, the present method and system are exemplified as being implemented in a portion of the supply route to the concrete manufacturing facility, but they may also be implemented continuously or intermittently at multiple locations on the supply route to the concrete manufacturing facility. By doing so, it is possible to achieve effects similar to or greater than those of the above-described embodiments.

[0050] Furthermore, in the above embodiments, the method is described as being performed on a path for feeding aggregate to a concrete manufacturing facility, and the system is described as being installed on a path for feeding aggregate to a concrete manufacturing facility. However, the method may be performed in a concrete manufacturing plant solely for heating, and the system may be installed in a concrete manufacturing plant as dedicated heating equipment. In this case, multiple belt conveyors may be arranged in a circular pattern to circulate the aggregate, or in multiple parallel rows to transport multiple aggregates in double rows. In this case, multiple microwave generators may be installed continuously or intermittently within a shield cover at multiple locations in the circulation or transport direction of the aggregate. By doing so, it is possible to achieve the same effects as those of the above-described embodiments as equipment dedicated to heating aggregates. [Explanation of symbols]

[0051] A. Aggregate that can be heated by microwave irradiation (electric furnace oxidized slag aggregate containing surface water) M Microwave generator S Shield Area F Shielding equipment B Conveyor B1, B2 conveyor belt b1 Conveyor frame b2 Conveyor roller b3 Conveyor belt D Drive roller C-cover C1, C2 shield cover C3 Shield Cover C31 outer periphery C32 end CP strut BP Batcher Plant BP1 Material Storage Bin BP2 Weighing Bottle BP3 Mixer BP4 Hopper P1 Cement silo P2 Aggregate Silo P3 Waterworks P4 Admixture facility

Claims

1. 1. A method for heating concrete aggregate, comprising heating concrete aggregate contained in concrete material by a heating device during a process of feeding the concrete material to a concrete manufacturing facility, the method comprising: The concrete aggregate is made of electric furnace oxidized slag, A microwave generator is used as the heating device, In the process of feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing facility, the electric furnace oxidizing slag aggregate is directly heated by irradiating the electric furnace oxidizing slag aggregate with microwaves from the microwave generator.

1. A method for heating aggregate for concrete, comprising:

2. 2. A method for heating aggregate for concrete according to claim 1, wherein a shielded area for preventing leakage of microwaves is defined on a feed path for feeding the electric furnace oxidizing slag aggregate to a concrete manufacturing facility, and a microwave generator is installed in the shielded area.

3. 3. A method for heating aggregate for concrete according to claim 2, wherein the feed path for feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing facility is composed of a conveyor for transporting the electric furnace oxidizing slag aggregate and a hollow cylindrical cover surrounding the conveyor, and the cover is made of a metal material capable of blocking microwaves, thereby defining a shielded area on the feed path.

4. 3. A method for heating aggregate for concrete according to claim 2, wherein the feed path for feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing equipment is composed of a conveyor for transporting the electric furnace oxidizing slag aggregate and a hollow cylindrical cover surrounding the conveyor, and a hollow cylindrical shield cover made of a metal material capable of blocking microwaves is placed inside the cover to define a shielded area on the feed path.

5. A heating system used in the method for heating aggregate for concrete according to any one of claims 1 to 4, a shielding facility disposed on a feed path for feeding the electric furnace oxidizing slag aggregate to the concrete manufacturing facility, the shielding facility preventing microwave leakage; a microwave generator installed in the shielding equipment for irradiating microwaves toward the electric furnace oxidizing slag aggregate; It consists of A heating system for concrete aggregates.

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