KR101411262B1 - High-efficient and uniformly-heating system for construction of slab using microwave, and construction method of slab using the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a heating system for slab construction using a microwave and a slab construction method using the same, and more particularly, to a method for heating a steel plate of a slab die using a heating system for slab construction using a microwave, Provided is a heating system for slab construction, which can shorten the initial hydration time of concrete laid on the upper part of a steel plate, in particular, a slab construction period during a period in which the outside air temperature is low, and a slab construction method using the same.
When the slab is constructed using the microwave heating system according to the present invention, it is possible to shorten the curing period by shortening the initial water hydration time of the concrete, thereby dramatically shortening the total air. In the thermal curing process, It is possible to heat-cure the concrete without using it, and in particular to solve the problem of non-uniform heating and possibility of cracking due to this.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-efficiency uniform heating system for slab construction using a microwave, and a slab construction method using the microwave,

The present invention relates to a high efficiency uniform heating system for slab construction using a microwave and a slab construction method using the same. More particularly, the present invention relates to a high efficiency uniform heating system for a slab installation using a microwave, The present invention relates to a high efficiency uniform heating system and a slab construction method using the same, which can shorten the initial hydration time of concrete placed on the steel plate by heating a steel plate of a slab form by using a uniform heat generation system.

A form is a temporary facility used during the process of manufacturing a concrete structure until the concrete is cured. Since it is a temporary facility, it is common to separate and reuse concrete when curing is completed.

In order to construct architectural structures and civil engineering structures such as apartment buildings, residential complex buildings, and office buildings, the columns or walls of the building to be constructed are installed, the slab formwork is installed on the upper part of the building, the reinforcing bars are laid, Lt; / RTI >

In the construction of the slab of the building, conventionally, when the external temperature is high as in the summer season, the hydration reaction of the concrete normally progresses and there is no problem in the construction. However, when the outside air temperature is low as in winter, Therefore, the construction period becomes longer.

Conventionally, in order to construct a building slab when the outside air temperature is low, a method of raising the temperature by inserting a heating wire into the slab former is used, and the upper part is shielded from the outside by using a smelting furnace or a hot air blower So that the temperature of the internal space was kept constant.

However, in the method of using the mold in which the heating wire is embedded, a complicated electric work is required because the heating wire must be installed in the formwork, and electricity is continuously supplied to the heating wire, so that a huge amount of electricity is consumed. In addition, the method of maintaining the temperature by using lignite or hot air blowing in the upper part of the reclamation membrane has a problem that a large amount of toxic gas is generated in the lignite fireplace and thus environmental safety of workers is hardly guaranteed, There is a problem that a large amount of oil, gas, and electricity is consumed for the operation of the hot air.

In the case of the conventional method, the application was limited due to the above problems. Even if the construction was carried out, there was a problem that the construction of the winter was difficult due to safety problems, environmental problems, concrete quality deterioration and excessive cost.

In order to solve the problems of the prior art, the applicant of the present invention accelerated the curing of the concrete by raising the temperature of the mold by microwave without using a huge amount of electricity, oil, gas, A new construction technique has been proposed to shorten the period. (Korean Patent Application No. 10-2012-0031331 and Patent Registration No. 10-1322597) When the above patented technology is used, the heat efficiency and the effect of promoting concrete curing by this method are excellent, so that the construction of the concrete slab in the winter season can be effectively performed, And the heat transfer efficiency is somewhat lacking.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a slab form steel plate The heat generation efficiency and the heat transfer efficiency are excellent and the uniform heat generation can be achieved as a whole, so that the concrete strength of the slab And to provide a new environmentally friendly high efficiency uniform heating system capable of improving the quality of the exhaust gas.

Another object of the present invention is to provide a slab construction method capable of accelerating and curing high quality slab concrete using the new environmentally friendly high efficiency uniform heating system according to the present invention.

In order to achieve the first object of the present invention,

A plurality of steel plate supporting members provided parallel to each other at regular intervals in a lower part of the steel plate and a lower steel plate supporting member inserted into a space surrounded by a beam vertically provided to the steel plate supporting member at a lower portion of the steel plate supporting member, A heating system attached to a lower part of the steel plate of the formwork and generating a microwave by power supply,

A microwave generator for generating microwaves;

A waveguide connected at one end to the microwave generator and having a pipe shape for receiving a microwave generated from the microwave generator and transmitting the received microwave to the reflector;

A reflector having a sealed inner space for diffusing the microwave transmitted from the waveguide and sharing the inner space with the waveguide;

A distribution plate provided on the opposite side with respect to the waveguide and the sealed inner space and having a distribution hole for passing a microwave that is irregularly reflected by the reflection portion;

A heating element which is provided on the opposite side of the reflection part and is in close contact with the distribution plate and absorbs microwaves passing through the distribution hole to generate heat;

And a cavity cover which is connected to the upper ends of the side plates and forms a closed reflective part together with the side plates, the side cover being connected to both side ends of the bottom cover, A cavity for transferring heat generated from the heating element to the outside; And

A temperature controller for controlling a heat generation temperature of the heating element;

And,

Wherein the heating element is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less and a sphericity of 0.5 or more and silicon carbide particles having a particle size of 5.0 mm or less at a ratio of 100: 0.1 to 100 by weight. System.

In order to achieve the second object of the present invention,

(a) a plurality of steel plate supporting members provided parallel to each other at regular intervals on an upper steel plate of the slab formwork and a lower portion of the steel plate, and a space surrounded by the beam vertically provided at the lower portion of the steel plate supporting member, Inserting a heating system for slab construction using a microwave according to the present invention and attaching the heating system to a lower part of a steel plate of the slab formwork to manufacture a heating form for a slab;

(b) horizontally supporting the heat-generating dies for slabs manufactured using the same method, placing reinforcing bars on the steel plates of the slab formers and casting concrete;

(c) supplying power to the heating system for slab construction using the microwave and curing the poured concrete; And

(d) demolding the heating die for the slab from the cured slab concrete

The present invention provides a method of constructing a slab.

Features and advantages of a heating system for slab construction using a microwave according to the present invention and a slab construction method using the same are as follows.

1. A heating system in the form of a module that generates heat by a microwave is divided into an upper steel plate of a slab form, a steel plate supporting member provided below the steel plate, and a space surrounded by a beam provided at a right angle to the steel plate supporting member, So that a complicated electric wiring work such as a separate heating line work is not required. In addition, since the heating system is integrated with the slab formwork, it is not necessary to separate the slab formwork, and after the concrete curing, the integrated slab formwork is merely dismantled and workability is excellent.

2. In addition, the heating system for slab construction, which is heated by the microwave used in the present invention, reaches a desired temperature in a short time even if electricity is supplied for only a few minutes to several tens of minutes. Since the temperature does not easily cool afterwards, Therefore, the energy consumption can be significantly reduced compared to the conventional heating line method, so that the energy efficiency can be improved.

3. The heating system for slab construction, which is heated by the microwave used in the present invention, can be easily changed in accordance with the shape of the slab formwork, so that it can be freely manufactured in any form such as an indoor or outdoor work Can be utilized.

4. The heating system for slab construction, which is heated by the microwave used in the present invention, can be applied irrespective of the external temperature, so that the construction period is shortened when the outside air temperature is low, such as in winter or winter It has a great effect.

5. According to the heating system for slab construction using the microwave according to the present invention and the slab construction method using the same, it is possible to replace the existing coal burning stove, hot air heater, steam, etc., Since it is not necessary to consume fuel such as gas, it is possible to reduce the construction cost, thus enabling economical construction.

6. In addition, a heating element that generates heat by microwaves is used in combination with materials having excellent heat generation efficiency, that is, energy efficiency, and materials having energy transfer efficiency, that is, excellent energy release rate, at an optimum ratio. The heat uniformity is remarkably improved as compared with the conventional materials.

7. Also, since the internal structure of the heating system is designed so that the microwave can be efficiently distributed as a whole in order to prevent the microwave from being irradiated only locally, the uniform heating effect can be further increased in addition to the material design.

8. Therefore, it can solve the problem of crack generation due to the existing local overheating and the problem of unevenness of physical properties such as compressive strength, so that it is possible to construct high quality such as securing homogeneous physical properties when concrete slab is applied.

1 is a flowchart showing a process of constructing a concrete building in a middle of winter (winter season, etc.) using a conventional mold.
2 is a plan view showing an example of a heating system for slab installation using microwaves according to an embodiment of the present invention.
3 is a side sectional view showing an example of a heating system for slab installation using a microwave according to an embodiment of the present invention.
4A to 4D are plan views showing some examples of distribution plates applied to a heating system for slab construction using a microwave according to an embodiment of the present invention.
FIG. 5 shows an outer shape of a heating element used in a heating system for slab construction using a microwave according to an embodiment of the present invention.
6 is a graph showing internal energy and emission energy evaluation results of rapid cooling steel slag, silicon carbide, and mixtures thereof according to an embodiment of the present invention.
7 is a flowchart showing an example of a tunnel slab construction method using a heating system for slab construction using a microwave according to the present invention.
Fig. 8 is a perspective view showing that the heating die set for a slab according to the present invention is supported by a shovel as an entire constitution. Fig.
Fig. 9 is a perspective view showing only a heating die set for slabs as a whole as a whole constitution of a heating die set for slabs according to the present invention.
10 is a cross-sectional view of a heat-generating die set for a slab according to the present invention, with reference to the CC plane.
11 is an exploded perspective view of a heating die set for a slab according to the present invention.

In the present invention, the meaning of " ideal " means that the value is not less than the corresponding value, and generally has an upper limit that is reasonably understandable in the field to which the present technology belongs. Means that the invention has a lower limit of common sense and reasonably understandable in the field to which the present invention belongs, it should be understood as an expression for expressing the invention in a simple and clear manner.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

FIG. 1 is a view showing a process of constructing a building wall surface and a floor slab of Korea-China (such as winter) by a conventional general steel formwork. In the conventional method, a mold is firstly made and installed on the outer wall of the building, and after the concrete is poured into the concrete, the temperature is raised by the natural hydration heat or the heat is supplied by the hot air or the heating wire from the outside, First concrete is cured. After that, the formwork of the inner wall of the building is removed and a mold for the construction of the upper floor slab is installed. Then, the inside of the building is closed with a covering film and the temperature is maintained at about 10 ° C by using a lignite furnace or hot air. Cure. When the insulation is cured for about 3 ~ 4 days, the wall strength is enough to construct the upper layer. Therefore, the reinforcement for the upper floor slab and the slab concrete installation work are performed and the poured slab concrete is cured. The curing of the upper floor slab concrete is carried out by installing a ventilation membrane to prevent direct exposure to the outside air, and heating and curing the upper part of the exposed concrete by using a lignite furnace or a hot air blower inside. When the curing of the outer wall of the building is completed, it is common to use a method of constructing a building wall and a floor slab by installing a mold on the outer wall of the upper building and repeating the same process.

Such a conventional method has a problem in that hydration does not progress well when the external temperature is low as in winter, and it is necessary to use a device such as lignite or hot air to cure the internal heat, And the problem of difficulty in securing quality such as strength and durability of concrete.

The present invention is a technique for solving the problems of the existing construction method, and it is not different from the existing technology in that the construction of the wall and the curing of the concrete on the exposed concrete are cured by thermal insulation.

However, according to the present invention, when the heating system using the microwave is attached to the lower part of the steel plate of the slab form, power is supplied to the heating system to induce heat generation, The method of heating the steel sheet is different.

FIG. 2 is a plan view showing an example of a heating system for slab installation using a microwave according to an embodiment of the present invention, and FIG. 3 is a side sectional view thereof.

2 and 3, the heating system 20 for slab installation using a microwave according to the present invention includes:

A microwave generator 21 for generating a microwave;

A waveguide 22 connected at one end to the microwave generator 21 and having a pipe shape for receiving microwave generated from the microwave generator and transmitting the received microwave to the reflector;

A reflector 24 having a sealed inner space 23 for diffusing the microwave transmitted from the waveguide and sharing the inner space with the waveguide;

A distribution plate (25) provided on the opposite side of the waveguide and the sealed inner space and having a distribution hole (26) for passing a microwave that is irregularly reflected by the reflection portion;

A heating element (27) provided on the opposite side of the reflection part to closely contact the distribution plate and absorbing microwaves passing through the distribution hole to generate heat;

A bottom plate (28-1) provided outside the heating element in close contact with a heating element, a side plate (28-2) connected to both side ends integrally with the bottom plate, and an upper A cavity 28 composed of a cavity cover 28-3 forming a closed reflective part 24 and transferring heat generated from the heating element to the outside; And

A temperature controller 33 for controlling the temperature of the heat generated by the heating element,

And,

The heating element is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less, a sphericity of 0.5 or more, and silicon carbide particles having a particle size of 5.0 mm or less at a weight ratio of 100: 0.1 to 100.

The heating system 20 for slab installation using the microwave according to the present invention comprises an upper steel plate of a slab form and a plurality of steel plate supporting members provided at a predetermined interval in parallel to each other at a lower portion of the steel plate, The steel plate is inserted into a space surrounded by a beam provided perpendicularly to the steel plate supporting member and attached to the lower part of the steel plate of the slab formwork, and microwave is generated by power supply to generate heat. (See FIGS. 8 to 11)

In the present invention, the microwave generator or other magnetron is connected to a power source by a high voltage transformer 29, and an air-cooled cooling device (for example, a cooling fan 30) for cooling the heat generated in the microwave generator, It is preferable that an apparatus is provided.

In addition, it is preferable that a protective cover 31 for protecting the internal devices such as the microwave generator, the high voltage transformer, and the cooling device is fixed to the cavity cover 28-3.

A temperature sensor 32 for detecting the temperature of the cavity is provided inside or outside the cavity 28. The temperature sensor is connected to the temperature controller 33 so that the microwave generator and the cooling device In order to control the operation of the vehicle.

In addition, it is preferable that a case 34 for protecting internal devices is provided outside the microwave generator, the waveguide, and the cavity. The case 34 may be made of a plastic material to reduce weight and may be manufactured by injection molding or extrusion molding.

2 and 3, the temperature controller 33 is provided outside, but it is more preferable that the temperature controller 33 is installed in the case 34 so that the display unit can be seen from the outside.

Further, it is preferable that the heat insulating material 35 is attached to the cavity cover 28-3 in order to prevent the heat generated inside from being diverted to the opposite side of the heating object. Glass wool, gypsum, heat-resistant plastic, heat-resistant ceramic, heat-resistant paper or stone powder can be used as the material of the heat-insulating material.

Wherein the heating element comprises a metal oxide including an iron oxide compound and is heated by a microwave of 300 MHz to 300 GHz. Specifically, the heating element uses a heating element composition that generates heat by using the microwave described above. Specifically, the heating element has a quenching steel slag having a particle size of 5.0 mm or less, a sphericity of 0.5 or more, and silicon carbide particles having a particle size of 5.0 mm or less, Or a cured product obtained by mixing cement in a weight ratio of 0.1 to 50 to 100 parts by weight of the ceramic composition and curing the mixture by hydration with an appropriate amount of water is used. In this case, when the ceramic composition is used as it is, it is preferable to adhere to the bottom plate using a heat-resistant bond. For example, the ceramic composition may be mixed with the heat-resistant bond and attached to the bottom plate.

The heating system for slab construction using the microwave can quickly heat the surface of the slab concrete to be heated through the heating element only by generating microwaves by applying power to the micro generator.

The microwave generator, the waveguide, and the heating element are preferably installed in a modular fashion mounted inside the cavity, but the present invention is not limited thereto and various design modifications are possible.

In particular, it is preferable that the waveguide has a tubular shape in which one end thereof is directly connected to the microwave generator and the other end is connected to a reflector having a closed space therein.

The microwave generator (magnetron) is connected to the high voltage transformer and the high voltage transformer is connected to the external power source. The high voltage transformer transforms a commercial AC voltage input from the outside into a high voltage (for example, about 2 kilovolts [kV]) suitable for generating a high frequency and applies it to the magnetron. The magnetron generates high frequency oscillation by a high voltage applied from a high voltage transformer Thereby generating microwaves.

It is preferable to use the 2,450 MHz band in order to utilize the advantage of the microwave frequency, such as Industrial, Scientific and Medical (ISM) frequency. However, it is not limited to this, Microwave having a frequency in the range of 300 GHz can be used in various ways.

A cooling device (e.g., a cooling fan) is installed around the magnetron to cool the high temperature generated by the magnetron when the magnetron is driven. A cooling device is connected to the fan motor. A voltage (commercial AC voltage) When the motor is applied to the motor, the fan motor is operated, and the fan of the cooling device is driven by the fan motor to blow the external cool air to the magnetron, thereby cooling the high temperature generated in the magnetron.

The microwave generator is fixed to the side surface of one end of the waveguide by a fixing bracket and is connected to the side surface of one end of the waveguide by a coupling tube protruding from the back surface of the microwave generator, Can be delivered to the department.

These microwave generators are consumables and must be replaced when they reach their end of life. The microwave generator in the heating system for slab construction using the microwave according to the present invention can be easily replaced as if replacing a bulb. Therefore, the heating system for slab construction according to the present invention can be used semi-permanently only when the microwave generator is periodically or defective.

In the present invention, the heating element is made of a heat resistant plate having a long length and a ceramic material (see FIG. 5). When a microwave is irradiated on a ceramic material plate having a high dielectric loss factor, Heat is generated by dipole rotation.

Meanwhile, as described above, since the microwave generator is installed on the side surface of one end of the waveguide to supply microwaves, a portion directly connected to the waveguide in the reflection portion receives a lot of microwaves and receives less influence of microwaves. In order to smoothly diffuse the microwave, a distribution plate is disposed in the middle of the distribution plate so that the microwave is substantially reflected in the distribution plate, so that a certain degree of microwave can be absorbed .

Some forms of distribution plates with distribution holes in the present invention are as shown in Figs. 4A to 4D.

As shown in FIGS. 4A to 4D, it is preferable that the distribution plate is symmetrically disposed around the waveguide without forming a distribution hole in the front portion of the waveguide. However, they are not necessarily provided symmetrically but may be provided asymmetrically. In this case, the shape of the dispensing hole may be variously designed such as a circle, an ellipse, and a square.

Further, since the density of the microwave is decreased as the distance from the waveguide decreases, it is preferable that the size of the distribution hole increases as the distance from the waveguide increases, so that the heat is further generated farther from the waveguide, Do.

Also, in the present invention, since the waveguide can be biased not only at the center of the distribution plate, but also at one point away from the waveguide, it is preferable that the distribution hole is optimally designed so that absorption of the microwave is smooth.

In the present invention, the material used as the distribution plate is preferably a material that reflects without absorbing microwaves, and examples thereof include steel, aluminum, or copper.

Further, in the present invention, it is preferable that the distribution plate has a smooth plate shape or a plate shape which is uneven on the surface.

Hereinafter, the heating element 27 used in the heating system for slab installation using the microwave used in the present invention will be described in detail.

5 shows an outer shape of the heating body 27 according to an embodiment of the present invention. 5, the heating element according to the present invention is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less, a sphericity of 0.5 or more, and silicon carbide particles having a particle size of 5.0 mm or less at a weight ratio of 100: 0.1 to 100 desirable. In the present invention, the particle size of the rapid-cooling steelmaking slag is more preferably 3.0 mm or less, and still more preferably 1.0 mm or less. In addition, in the present invention, the silicon carbide particles preferably have a particle size of 3.0 mm or less, more preferably 1.0 mm or less. The mixing weight ratio of the rapid-cooling steelmaking slag to the silicon carbide particles is preferably 100: 0.1 to 50, more preferably 100: 0.5 to 20. The heating element may be used as the ceramic composition itself. However, the curing composition 10 may be obtained by mixing 100 parts by weight of the ceramic composition with cement in a weight ratio of 0.1 to 50, adding an appropriate amount of water and kneading, Is more preferably used. In this case, since the content of the ceramic composition is high and a small amount of cement is contained, it shows a dark gray or light black color from the outside. Fig. 5 shows the outer shape of the cured product. The cured product may be used as it is in the shape of Fig. 5, or may be used in a state where the surface thereof is processed flat. When the ceramic composition is used as it is, it is preferable to adhere to the bottom plate using a heat-resistant bond. The heat-resistant bond is exemplified by a ceramic bond, and it is also possible to use the heat-resistant bond and the ceramic composition in a cured state by mixing.

Conventionally, the slag discharged from a steel mill is treated by discharging the slag into a slag pot disposed in a lower portion of a converter or an electric furnace and then discharging the slag to a treatment plant. In the conventional treatment method, a large amount of water is sprayed on the discharged slag to cool the slag The iron content in the slag after solidification and subsequent crushing process is selected through a magnetic separator to be used as a steel source, and the remaining slag is mostly used as an aggregate such as landfill or road pavement because it has no special purpose. However, when the waste slag is simply buried in the landfill, the cost of the landfill is inconvenient and the burden of the landfill is considerably burdensome if the amount of the landfill is large. Therefore, there is an environmental problem, .

The steel slag cooled by the cooling (slow cooling) is called slow cooling steel slag and contains a large amount of free lime (free CaO), and this free lime reacts with water in the road pavement to produce calcium hydroxide (Ca (OH) ₂ ). Since the calcium hydroxide formed is bulky and prone to be differentiated from free lime, there is a problem that when used as a roadbed material, roads are raised, and the calcium hydroxide differentiated causes pollution of the atmosphere and water quality. In addition, because calcium hydroxide is alkaline, it causes soil contamination and its use as road pavement aggregate is also very limited.

Rapid cooling steel slag was introduced to solve the problem of the slow cooling steel slag. Rapid cooling steel slag can be produced by a method of dropping a hot molten slag and spraying a high speed air stream to shake a hot molten slag to rapidly cool it by a high speed air stream and to make it into a fine powder form. When this method is used, slag in the form of fine powder is produced instead of bulk slag, so there is no need of separate crushing process and the effect of reducing the amount of free limes. However, since conventional quench steelmaking slag has focused on reducing the amount of free limes and using it as a construction aggregate, the development of new capacity has been sluggish.

The present invention has developed a new application of such a rapid steelmaking slag, and the rapid cooling steel slag absorbs microwaves and finds a property of generating heat, and uses this as a heat generating material.

The rapid-cooling steelmaking slag used in the present invention is not produced by using conventional quenching steelmaking slag which is conventionally used but is manufactured in a refined form by using a special sorting and refining method.

Hereinafter, such a selection / purification method will be described in more detail.

First, an example of a method of manufacturing the rapid cooling steelmaking slag according to the present invention is as follows. That is, the rapid cooling steelmaking slag having a particle diameter of 5.0 mm or less is selected through a sieving process in a first step, and a magnetic separator having a magnetic force of 500 gauss or more, preferably 700 to 5,000 gauss is used as a second step Only the particles having the microwave absorption efficiency required in the present invention are selected, and only spherical particles having a spherical modulus of 0.5 or more are selected through a spherical separator. At this time, the above-described seeding process, spherical sorting process, and magnetic force selecting process may be performed in sequence or simultaneously, all of which are included in the scope of the present invention. In the present invention, the rapid-cooling steelmaking slag obtained through such a special sorting and refining operation is simply referred to as " MIP (Microwave-irradiated pyrogen) ".

In the present invention, the particle size of the rapid cooling steelmaking slag is preferably 5.0 mm or less, and the spherical ratio is required to be 0.5 or more. If the particle size exceeds 5.0 mm, if the particle size is too large, the total specific surface area is not large and the heat generation efficiency and heat transfer efficiency are deteriorated. The sphericity ratio is, in other words, the shape factor, which means the ratio of the smallest diameter to the longest side diameter of the particles. If the sphericity of the rapid cooling steel slag having a sphericity ratio of less than 0.5 results in a distorted shape, In this case, the spark may occur. Since the energy is concentrated only at the pointed portion or the angled portion and energy loss occurs, the efficiency of heat generation in the whole particle is lowered. Therefore, the sphericity should be selected to be 0.5 or more do. This rapid steelmaking slag has the characteristics of a semi-insulator between the conductor and the non-conductor, so that absorption heating and induction heating are performed, and the internal microwave is transferred according to the charging state. That is, when the microwave is applied to the continuous spherical rapid cooling steel making slag, the microwave is transferred along the rapid cooling steel slag due to the surface effect, and absorption heating and induction heating are performed in the adjacent rapid cooling steel slag as before.

The present inventors have proposed a technique of utilizing a rapid-cooling steelmaking slag composition as a heating element to be generated by a microwave through the above-mentioned patent (Korean Patent Application No. 10-2011-0032313, Patent Registration No. 1314384).

However, the rapid-cooling steelmaking slag composition described in the above patent has a very high energy generated by the specific heat and the microwave, but it is not so fast in terms of the transfer speed for transferring it to the periphery, i.e., the energy release rate, And it is found that there is a problem that it takes a lot of time and the local fever progresses. As a result of repeated research efforts to overcome these problems, it has been found that a combination of quenching steel slag and silicon carbide (SiC) can be solved. That is, in the case of silicon carbide, which has been known as a material capable of being heated by microwaves, the energy generated by the specific heat and microwave is lower than that of the rapid-cooling steel slag as shown in Table 1 below, The rate of transfer is much higher than that of rapid cooling steelmaking slag. Accordingly, the present inventors have found that when mixed with silicon carbide having a high energy transfer rate, problems of low energy transfer and uneven heat generation, which were problems in using the conventional quenching steel slag alone, can be solved.

Rapid cooling steelmaking slag (MIP) Silicon carbide (silicon carbide) specific heat 0.1807 Cal / g 占 폚 0.1624 Cal / g 占 폚 Energy release rate 0.343 W / m · K 170 W / m · K

Table 2 shows the results of measurement of heat efficiency by microwave using silicon carbide, MIP and water. Using Equation 1, the thermal energy used to raise the temperature is expressed as the used power, and the energy efficiency is calculated based on the ratio of the used power according to the input power using Equation 2.

unit sign Silicon carbide (SiC) MIP water Mass (g) M 200 200 200 Specific heat (Cal / g · ° C) Cp 0.1624 0.1807 One Temperature difference (℃) ΔT 79.1 152.8 22.5 Time (seconds) t 60 60 60 Power (W) P 179.8 386.5 315 Incoming power (W) Pin 700 700 700 Energy efficiency η 0.26 0.55 0.45

(수식1)

(수식2)

(Equation 1)

(Equation 2)

As shown in the above Table 2, the efficiency of microwave heating for the same input power is more than twice that of silicon carbide for MIP.

The internal energy and emission energy of the MIP, silicon carbide, and mixtures thereof obtained through the above experiment are shown in FIG. As shown in FIG. 6, the MIP heating element has a high energy generation rate but a low transfer rate. Conversely, silicon carbide has a relatively small energy generation rate, You can get both effects of delivery. (This experiment was conducted by Korea Polymer Research Institute, Korea). Specific heat analysis was performed using Perkin-Elmer DSC 4000 by KS M 3049 method. Thermal conductivity was measured by Mathis TC -30. In the case of the mixture of the present invention, MIP: silicon carbide was mixed in a weight ratio of 100: 0.5.

As can be seen from the experimental results shown in FIG. 6, in the case of MIP alone, the internal energy is raised by microwave irradiation, but the emission energy is low. In the case of silicon carbide alone, the internal energy raised by microwave irradiation is not only the MIP, Is very high.

Therefore, when the MIP and silicon carbide are mixed with each other using such a characteristic, the internal energy is relatively high and the energy release property is maintained high. Thus, the problem of using the existing MIP alone can be solved.

In the present invention, such MIP, that is, a rapid cooling steel making slag having a particle size of 5.0 mm or less and a sphericity of 0.5 or more is mixed with silicon carbide particles having a particle size of 5.0 mm or less at an optimum ratio. Since silicon carbide is about 30 to 50 times higher in price than MIP in terms of unit cost, it is not economically advantageous to use a large amount of silicon carbide. Therefore, silicon carbide should be used in an optimum ratio. In the present invention, By weight, and more preferably 100: 0.1 to 50 parts by weight. If the silicon carbide is used in an amount of less than 0.1 part by weight based on 100 parts by weight of MIP, the energy transfer efficiency is lowered. Therefore, it is difficult to solve the problem when the conventional MIP is used alone. If the silicon carbide is used excessively in excess of 100 parts by weight, It is undesirable because the price may fall and the unit price may rise too much and the economic effect may decrease.

In the present invention, it is possible to use a ceramic composition containing an optimum ratio of rapid cooling steel slag (MIP) having a particle size of 5.0 mm or less and a sphericity of 0.5 or more and silicon carbide (SiC) particles having a particle size of 5.0 mm or less, May be mixed and used in a cured form. The reason for using such a cured form is that when the uncured particle (particle) form is used, the handling property is not good and there is a fear that the cement is caught in one side. In the case of cured cement, the latent heat is retained for a long time This is because there is also an effect. In the present invention, the cement mixed with the ceramic composition, for example, Portland cement, is preferably mixed with 100 parts by weight of the ceramic composition in a weight ratio of 0.1 to 50, and the mixture is hydrated by adding an appropriate amount of water, Whereby a cured product is obtained. In this case, the thickness of the cured product may vary depending on the application, and it is preferably 1 to 100 mm for general use.

In the present invention, the ceramic composition may further include a metal oxide, which is conventionally known to absorb microwaves. The content of the metal oxide is preferably in the range of 0.1 to 100 parts by weight, more preferably 0.5 to 50 parts by weight to be. The size of the ceramic composition is preferably 5.0 mm or less, more preferably 3.0 mm or less, and still more preferably 1.0 mm or less. Examples of such metal oxides are iron oxides, and specific examples thereof include Fe ₂ O ₃ , Fe ₃ O ₄ and FeO. Examples of other metal oxides include Al ₂ O ₃ , CaO, SiO ₂ , TiO ₂ , MgO, and the like.

In the present invention, a heating system is manufactured using a heating element that generates heat by the microwave, and the structure of the heating system is as described above.

The heating system according to the present invention is installed in a module form in the lower part of the steel plate of the slab formwork and is installed simply by supplying power, so that the work is easy, the temperature rise is fast due to the characteristics of the heating body material, There is an advantage that power consumption is not excessively consumed in order to maintain the set temperature. In addition, the quality of the cured concrete such as strength and durability can satisfy the required quality and above, and uniform quality can be ensured due to uniform heat generation.

In particular, when the outside temperature is low, such as during the winter or the cold, it is impossible to cure due to the natural hydration of the concrete, so that the concrete pouring process in winter is very limited. However, when the heating system for slab construction using the microwave according to the present invention is used, The temperature is supplied to the concrete to induce the temperature rise at the initial stage and then the natural hydration is promoted to promote the concrete curing.

Therefore, when the concrete is cured for a long period of time such as winter, early spring, and late autumn, it is almost equivalent to curing the concrete in the summer season.

Further, after completion of the slab construction, the slab dies on which the heating system module is mounted are simply demolded from the cured slab concrete, so that the work for separation and disassembly is also simple and easy to reuse.

7 is a flowchart showing an example of a slab construction method using a heating system for slab construction using a microwave according to the present invention.

7, a slab construction method according to an embodiment of the present invention includes:

(a) a plurality of steel plate supporting members provided parallel to each other at regular intervals on an upper steel plate of the slab formwork and a lower portion of the steel plate, and a space surrounded by the beam vertically provided at the lower portion of the steel plate supporting member, (S100) of inserting a heating system for slab construction using a microwave according to the present invention and attaching the heating system to a lower portion of a steel plate of the slab die to manufacture a heating die for a slab;

(b) horizontally supporting the heat-generating dies for slabs manufactured using the tillers, placing reinforcing bars on the steel plates of the slab dies and casting concrete (S200);

(c) supplying power to the heating system for slab installation using the microwave and curing the poured concrete (S300); And

(d) demolding the heating die for the slab from the cured slab concrete (S400)

.

In order to construct a slab, a slab formwork must first be manufactured. In the present invention, the upper steel plate and a plurality of steel plate supporting members provided parallel to each other at regular intervals below the steel plate, and a beam provided at right angles to the steel plate supporting member And a heating system for slab construction using the microwave according to the present invention is inserted into and attached to a slab die. More specifically, the heating system for slab construction using the microwave according to the present invention is inserted into a space surrounded by the upper steel plate, the steel plate supporting member and the beam of the slab formwork, and the heating system is attached to the lower part of the steel plate of the slab formwork, The heat mold is manufactured.

Fig. 8 is a perspective view showing that the heating die set for a slab according to the present invention is supported by a shovel as a whole, Fig. 9 is a perspective view showing only a heating die set for a slab, FIG. 11 is an exploded perspective view of a heat-generating die set for a slab according to the present invention. FIG.

8 to 11, the heating die set 100 for a slab according to the present invention is composed of an upper steel plate 52, a steel plate supporting member 51 and a beam 50. The steel plate, By inserting and attaching the heat generating system 20 for slab construction according to the present invention in a space surrounded by the member and the beam. At this time, it is preferable that a spacer 62 is attached to the heat generating system for attaching to the slab die steel plate 52 and the support member 60 is attached while pressing the support member 60 using bolts 61 from the outside.

Subsequently, the slab heat-generating die 100 is horizontally supported using a hoist 53 or the like, and a reinforcing bar is placed on the steel plate of the slab die and concrete is poured.

Then, power is supplied to the heating system for slab construction using the microwave according to the present invention mounted on the heating die for the slab, thereby heating the steel plate of the slab die to forcibly induce the initial hydration of the laid concrete. Since hydration of concrete is difficult to proceed when the outside air is low as in winter, inducing initial hydration of concrete by forced heating promotes curing of concrete since natural hydration proceeds thereafter.

The heating system for slab construction using the microwave according to the present invention and the slab construction method using the same have been described above. The heating system for slab construction using the microwave according to the present invention enables sufficient initial hydration even when the outside air temperature is low as in the case of winter, when the concrete slab is used for the early curing of concrete, so that the slab construction in winter can be effectively performed. Especially, it protects the concrete from the initial East Sea in the winter season, secures the required strength, accelerates the development of the strength by curing the concrete with rapid curing, and it is possible to shorten the length of the air and significantly reduce fuel consumption and power consumption Low-cost, and high-efficiency technology that can be reduced in cost, and is a low-carbon, eco-friendly technology that can be secured with no toxic gas such as the conventional method. Particularly, it is possible to solve the problem of nonuniform heating, which was a problem in the technique disclosed by the present inventors, and cracking due to the uneven heating.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, something to do.

10: MIP hardener
20: Heating system for tunnel concrete lining construction using microwave
21: Microwave generator 22: Waveguide
23: inner space 24:
25: Distribution board 26: Distribution board
27: heating element 28: cavity
28-1: bottom plate 28-2: side plate
28-3: Cavity cover 29: High voltage transformer
30: cooling fan 31: protective cover
32: temperature sensor 33: temperature controller
34: Case 35: Insulation
36: Capacitor 37: Capacitor holder
50: beam 51: steel plate supporting member
52: steel plate 53:
60: Support 61: Bolt
62: Spacer 100: Heat generating die set for slab

Claims (16)

A plurality of steel plate supporting members provided parallel to each other at regular intervals in a lower part of the steel plate and a lower steel plate supporting member inserted into a space surrounded by a beam vertically provided to the steel plate supporting member at a lower portion of the steel plate supporting member, A heating system attached to a lower part of the steel plate of the formwork and generating a microwave by power supply,
A microwave generator for generating microwaves;
A waveguide connected at one end to the microwave generator and having a pipe shape for receiving a microwave generated from the microwave generator and transmitting the received microwave to the reflector;
A reflector having a sealed inner space for diffusing the microwave transmitted from the waveguide and sharing the inner space with the waveguide;
A distribution plate provided on the opposite side with respect to the waveguide and the sealed inner space and having a distribution hole for passing a microwave that is irregularly reflected by the reflection portion;
A heating element which is provided on the opposite side of the reflection part and is in close contact with the distribution plate and absorbs microwaves passing through the distribution hole to generate heat;
And a cavity cover which is connected to the upper ends of the side plates and forms a closed reflective part together with the side plates, the side cover being connected to both side ends of the bottom cover, A cavity for transferring heat generated from the heating element to the outside; And
A temperature controller for controlling a heat generation temperature of the heating element;
And,
Wherein the heating element is a ceramic composition comprising a rapid cooling steel making slag having a particle size of 5.0 mm or less and a sphericity of 0.5 or more and silicon carbide particles having a particle size of 5.0 mm or less at a ratio of 100: 0.1 to 100 by weight. system.
The heating system according to claim 1, wherein the heating element is a cured body obtained by mixing 100 parts by weight of the ceramic composition with 0.1 to 50 parts by weight of the cement, and curing the mixture by hydration with water.
The heating system for a slab installation according to claim 1, wherein the heating element is attached to the bottom plate using a heat-resistant bond.
The heating system for a slab installation according to claim 1, wherein the microwave generator is connected to a power source by a high voltage transformer.
[6] The system of claim 4, wherein a cooling device for cooling the heat generated by the microwave generator is provided in the vicinity of the microwave generator.
The heating system for a slab installation using a microwave according to claim 5, wherein a protective cover for protecting the microwave generator, the high voltage transformer, and the cooling device is fixed to the cavity cover.
The microwave generator according to claim 1, wherein the cavity is provided with a temperature sensor for detecting the temperature of the cavity, and the temperature sensor is connected to the temperature controller to control the temperature of the microwave generator according to the temperature of the cavity. Construction heating system.
The heating system for a slab installation according to claim 1, wherein a case for protecting internal devices is provided outside the microwave generator, the waveguide, and the cavity.
The heating system for a slab installation according to claim 1, wherein a heat insulating material is attached to the cavity cover so as to prevent heat generated from the inside of the cavity cover from dissipating toward the opposite side of the concrete to be heated.
The heating system according to claim 1, wherein the distribution hole is not formed in a front portion of the waveguide but is symmetrically or asymmetrically formed around the waveguide.
The heating system for a slab installation according to claim 1, wherein the distribution holes are arranged so as to become larger as they are away from the waveguide.
The heating system according to claim 1, wherein the distribution hole is formed in a circular, elliptical or quadrangular shape.
The heating system for a slab installation according to claim 1, wherein the distribution plate is made of a steel material, aluminum material, or copper material.
The heating system for a slab installation according to claim 1, wherein the distribution plate is a plate-shaped or uneven plate-like shape.
The heating system for a slab installation according to claim 1, wherein the ceramic composition further comprises 0.1 to 100 parts by weight of a metal oxide.
(a) a plurality of steel plate supporting members provided parallel to each other at regular intervals on the upper steel plate of the slab formwork and the lower portion of the steel plate, and a space surrounded by a beam vertically provided at the lower portion of the steel plate supporting member, 1. A method of manufacturing a slab for a slab, comprising the steps of: (1) inserting a heating system for slab construction using a microwave and attaching the heating system to a lower portion of a steel plate of the slab formwork;
(b) horizontally supporting the heat-generating dies for slabs manufactured using the same method, placing reinforcing bars on the steel plates of the slab formers and casting concrete;
(c) supplying power to the heating system for slab construction using the microwave and curing the poured concrete; And
(d) demolding the heating die for the slab from the cured slab concrete
Wherein the slab is slab-shaped.

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