KR20220045782A - Air quenching apparatus using the plate comprising hole patterns - Google Patents

Abstract

The present invention relates to an air quenching apparatus comprising: a chamber which includes an inlet through which gas flows in, an outlet which discharges the introduced gas, and an inner space through which the gas passes to cool a product; and a plate which is located on the inlet of the chamber and includes a single or a plurality of hole patterns through which the gas passes. The air quenching apparatus of the present invention induces strong turbulent flow by adding the plate including the hole patterns to improve cooling efficiency and reduce energy consumption.

Description

Air quenching device using a plate including a hole pattern {AIR QUENCHING APPARATUS USING THE PLATE COMPRISING HOLE PATTERNS}

The present invention relates to an air quenching apparatus using a plate including a hole pattern, and more particularly, to an air quenching apparatus using a plate including a hole pattern in which cooling efficiency is improved by adding a plate including a hole pattern to a gas inlet. it's about

Quenching is one of the metal heat treatment processes, and it is an important process that determines properties such as strength and hardness of metal. In general, water or oil is used as a heat transfer medium for quenching, which can make a stronger metal due to a faster cooling rate. In addition, when a liquid heat transfer medium is used, it is accompanied by a waste disposal problem because the medium must be removed separately after quenching is finished.

Therefore, in recent years, as a heat transfer medium for quenching, air that allows uniform cooling and does not require separate removal has been in the spotlight. However, in the case of the method of quenching using air (gas), the cooling time is relatively slow compared to the method of quenching using water, so it is difficult to maximize the improvement in strength.

An object of the present invention is to solve the above problem, and to provide an air quenching device capable of inducing a strong turbulent flow by adding a plate including a hole pattern to a gas inlet.

Another object of the present invention is to provide an air quenching apparatus using a plate including a hole pattern capable of improving cooling efficiency and saving energy by inducing a strong turbulent flow.

According to one aspect of the present invention, a chamber 100 including an inlet 110 through which gas is introduced, an outlet 120 through which the introduced gas is discharged, and an internal space 130 through which the gas passes and cools the product. ); and a plate 200 located at the inlet of the chamber 100 and including a single or a plurality of hole patterns through which the gas passes; provides an air quenching device 10 comprising a.

The gas may have a turbulent flow in the inner space 130 .

The air quenching device is located outside the chamber 100, and a blower 300 for passing the gas through the hole pattern of the plate 200 and introducing it into the inner space 130; may further include .

The hole pattern may include a single or a plurality of holes, and the shape of the hole may include at least one shape selected from the group consisting of a circle, a semicircle, an ellipse, and combinations thereof.

The shape of the hole may include a shape of a circle.

The hole pattern includes a first hole; and a plurality of second holes surrounding the first hole.

The number of the second holes may be an integer of any one of 2 to 100.

The first hole and the second hole are each independently a circle, and a ratio (D ₂ /D ₁ ) of a diameter (D ₂ ) of the second hole to a diameter (D ₁ ) of the first hole may be 0.1 to 1 .

A ratio (D ₂ /D ₁ ) of a diameter (D ₂ ) of the second hole to a diameter (D ₁ ) of the first hole may be 0.2 to 0.7.

The plate has _a ratio ( _{(A 1 + A 2 ) /} A ₁ ) may be 1.5 to 15.

The plate has _a ratio ( _{(A 1 + A 2 ) /} A ₁ ) may be 2 to 10.

The average velocity of the gas after passing through the plate 200 may be faster than the average velocity of the gas before passing through the plate 200 .

The material of the plate 200 may be any one selected from the group consisting of steel, stainless steel, iron, aluminum, tin, and alloys thereof.

The outer wall of the chamber 100 may be an adiabatic wall.

The air quenching device may further comprise a conveyor 400 for transporting the product.

The conveyor 400 may be located in the inner space 130 .

The air quenching device is positioned on the conveyor, and may further include a pallet 500 for loading the product.

In the air quenching apparatus using a plate including a hole pattern of the present invention, a strong turbulent flow can be induced by adding a plate including a hole pattern to the gas inlet.

In addition, the present invention has the effect of improving cooling efficiency and saving energy by inducing a strong turbulent flow by adding a plate including a hole pattern.

In addition, the present invention can be applied to all manufacturing industries that use heat treatment of metals, such as automobiles, steel, and machinery industries, by using a high-efficiency and low-cost air quenching device with only a simple design change.

1 is a structural diagram of an air quenching device according to the present invention.
2 is a structural diagram showing the air quenching apparatus according to the present invention in 3D.
3 is a structural diagram of different plates according to the present invention.
4 is a result of comparing the simulation result of performing air quenching using the air quenching apparatus according to the present invention with an actual experiment.
5 is a graph comparing the average temperature of the product after 600 seconds according to the total area of holes and the number of holes.
6 is a view simulating the gas flow inside the apparatus according to Comparative Example 1 and Examples 1 to 5.
7 is a view showing the structure of a plate according to Preparation Example 16.
8 is a view showing the structure of a plate according to Preparation Example 17.
9 is a view showing the structure of a plate according to Preparation Example 18.
10 is a view showing the structure of a plate according to Preparation Example 19.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Also, terms including an ordinal number such as first, second, etc. to be used below may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, it may be named first without departing from the scope of the present invention.

In addition, when it is said that a component is "formed" or "stacked" on another component, it may be formed or laminated by being directly attached to the front surface or one surface on the surface of the other component, but in the middle It should be understood that there may be other components in the .

The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

1 is a structural diagram of an air quenching apparatus according to the present invention, and FIG. 2 is a structural diagram showing an air quenching apparatus according to the present invention in 3D. 3 is a structural diagram of different plates according to the present invention.

Hereinafter, an air quenching apparatus to which a plate including a hole pattern is applied will be described in detail with reference to FIGS. 1 to 3 . However, this is provided as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the claims to be described later.

The present invention provides a chamber 100 including an inlet 110 through which gas is introduced, an outlet 120 through which the introduced gas is discharged, and an internal space 130 through which the gas passes and cools the product; and a plate 200 located at the inlet of the chamber 100 and including a single or a plurality of hole patterns through which the gas passes; provides an air quenching device 10 comprising a.

Referring to FIG. 1 , the outlet 120 of the air quenching device 10 is an empty space in which nothing is installed.

The gas may have a turbulent flow in the inner space 130 .

The present invention was designed using Bernoulli's theorem, and when a fluid flows through a narrow passage, the speed increases. Since turbulent flow is generally much more efficient in heat transfer than laminar flow, it is very important to generate turbulent and vortex flows in devices such as heat exchangers where improved heat transfer is important.

The air quenching device is located outside the chamber 100, and a blower 300 for passing the gas through the hole pattern of the plate 200 and introducing it into the inner space 130; may further include .

The hole pattern may include a single or a plurality of holes, and the shape of the hole may include at least one shape selected from the group consisting of a circle, a semicircle, an ellipse, and combinations thereof. In the case of polygons, the pressure applied to the corners and vertices is different, so plate deformation and breakage may occur, so it is excluded.

The shape of the hole may include a shape of a circle.

The hole pattern includes a first hole; and a plurality of second holes surrounding the first hole.

The number of the second holes is an integer of 1 or more, and the number of the second holes varies depending on the type of the installed process, but may generally be an integer of any one of 2 to 100.

The first hole and the second hole are each a circle, and the ratio (D ₂ /D ₁ ) of the diameter (D ₂ ) of the second hole to the diameter (D ₁ ) of the first hole may be 0.1 to 1, preferably For example, it may be 0.2 to 0.7.

If the ratio (D ₂ /D ₁ ) of the diameter (D ₂ ) of the second hole and the diameter (D ₁ ) of the first hole is less than 0.1, the diameter (D ₂ ) of the second hole is small, which occurs in the quenching and conveying process If the design is undesirable in terms of maintenance due to the accumulation of foreign substances such as trace amounts of metal powder, and if it exceeds 1, the diameter of the _{second hole (D 2 )} The design is undesirable because it is difficult to be replaced by a fluid with a high flow rate that has passed through

The plate has _a ratio ( _{(A 1 + A 2 ) /} A ₁ ) may be 1.5 to 15, preferably 2 to 10.

The ratio ((A ₁ +A ₂ )/A ₁ ) of the sum (A ₁ +A ₂ ) of the area of the hole (A ₁ ) and the area of the plate excluding the hole (A ₂ ) and the area of the hole (A ₁ ) If is less than 1.5, it is undesirable because a relatively slow flow velocity is difficult to induce turbulence through the hole due to the large hole area. It is undesirable because the buoyancy force that tries to lift the plate without penetrating it acts.

An average velocity of the gas after passing through the plate may be higher than an average velocity of the gas before passing through the plate.

The material of the plate 200 may be any one selected from the group consisting of steel, stainless steel, iron, aluminum, tin, and alloys thereof.

The outer wall of the chamber 100 may be an adiabatic wall.

The air quenching device may further comprise a conveyor 400 for transporting the product.

The conveyor 400 may be located in the inner space 130 and may serve as an obstacle affecting the flow of gas.

The air quenching device is positioned on the conveyor, and may further include a pallet 500 for loading the product.

The present invention increases the speed as the gas introduced from the blower (blower) passes through the plate (cold air inlet) including the hole pattern, and the speed of the gas (air) passing through the conveyor, pallet and product of the device due to the increased speed The flow takes the form of turbulence. At this time, forced convection, the main heat transfer method of the product, is improved due to the turbulent flow, which has better heat transfer efficiency than laminar flow, and when air quenching is performed, the cooling performance of the device is improved.

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, the following examples are only provided for easier understanding of the present invention, and the content of the present invention is not limited by the examples.

[Example]

[Plate with hole pattern]

Preparation Example 1

An iron plate having a size of 2788mm (horizontal) × 1988mm (vertical) was prepared, and a hole was drilled in a circular shape with a diameter of 939.2mm to prepare a plate including one hole.

Preparation Examples 2 to 15

Preparation Examples 2 to 15 were prepared in the same manner as in Preparation Example 1 by varying the number, total area, and diameter of the holes, and the contents are described in Table 1 below. In addition, the structure of the manufactured plate can be confirmed through FIG. 3 , and four dark rectangles indicate a conveyor and circles indicate a hall.

In addition, Control Example 1 (A) shows a case in which a separate plate is not installed, and in Preparation Examples 1 (B) to 15 (P), the number, diameter, and area of the holes are different, and a specific pattern is not applied to the holes. They were arranged at uniform intervals proportional to the size.

plate Number of holes (pieces) Total area of the hall (m ² ) Hole diameter (mm) Control Example 1 (A) - 5.542 (total area of plate) - Preparation Example 1 (B) One 2.771 939.2 Preparation Example 2 (C) 2 2.771 664.1 Production Example 3 (D) 4 2.771 469.6 Preparation 4 (E) 16 2.771 234.8 Production Example 5 (F) 64 2.771 117.4 Preparation 6 (G) One 1.386 664.2 Preparation 7 (H) 2 1.386 469.7 Preparation 8 (I) 4 1.386 332.1 Preparation 9 (J) 16 1.386 166.1 Preparation 10 (K) 64 1.386 83.0 Production Example 11 (L) One 0.693 469.7 Preparation 12 (M) 2 0.693 332.1 Preparation 13 (N) 4 0.693 234.8 Preparation 14 (O) 16 0.693 117.4 Preparation 15 (P) 64 0.693 58.7

Preparation Examples 16 to 19

Preparation Examples 16 to 19 were prepared in the same manner as in Preparation Example 1 by varying the number, total area, and diameter of the holes, and the contents are described in Table 2 below. In addition, the structure of the manufactured plate can be confirmed through FIGS. 7 to 10 .

plate hole pattern shape Number of holes (pcs) Total area of the hall (m ² ) Hole diameter (mm) Preparation 16 (FIG. 7) A flower shape with 8 diameters covering a large-diameter hole 108 0.693 1st hole: 4.952 (large diameter)
2nd hole: 2.476 (small diameter) Preparation 17 (FIG. 8) A regular arrangement of large and small diameter holes 108 0.693 1st hole: 4.952 (large diameter)
2nd hole: 2.476 (small diameter) Preparation 18
(Fig. 9) A shape in which large-diameter and small-diameter holes are randomly arranged. 108 0.693 1st hole: 4.952 (large diameter)
2nd hole: 2.476 (small diameter) Preparation 19 (FIG. 10) Hole pattern of equal size and spacing distribution 108 0.693 2.8584

[Air quenching device]

Example 1

The chamber of the air quenching device is manufactured in a size of 2788mm (horizontal: x-axis) × 1988mm (vertical: y-axis) × 1600mm (height: z-axis), and the plate prepared according to Preparation Example 1 is installed in a position adjacent to the inlet did And using a blower (blower) to supply cold air having a temperature of 353.15K at a flow rate of 3500 m ³ / min, and the cold air is air. At this time, the density of the air is 0.9994kg / m ³ at 355.13K, the specific heat capacity is 1008J / kg·K, and the thermal conductivity is 0.02953W / m·K.

CFD modeling was performed in three dimensions using commercial software Star CCM + 12.04, and the target product to be cooled using the air quencher was modeled by simplifying the shape of the cylinder block of the engine used in the automobile industry, and the physical The properties and mass are modeled to produce the same heat capacity as the actual product. The initial temperature of the product was 808.15K, and the surface was smooth without roughness. In addition, the material of the product was 7075 aluminum alloy, and the density was 2,810kg / m ³ , the heat capacity was 960J / kg·K, and the thermal conductivity was 130W / m·K.

Examples 2 to 19

An air quenching device was manufactured in the same manner as in Example 1, except that the plates prepared according to Preparation Examples 2 to 19 were respectively installed instead of installing the plates prepared according to Preparation Example 1 in Example 1.

Comparative Example 1: Air quenching device

In Example 1, an air quenching apparatus was manufactured in the same manner as in Example 1, except that a separate plate was not installed instead of installing the plate prepared according to Preparation Example 1.

[Test Example]

Test Example 1: Simulation Results

4 is a result of comparing the simulation result of performing air quenching using the air quenching apparatus according to the present invention with an actual experiment. The airflow simulation inside the device was modeled using the RANS equation, and the turbulence was modeled as a coupling simulation based on the standard k-ε model.

Simulations and actual experiments were conducted under the same conditions as those of Example 1 described above.

According to Figure 4, when looking at the enlarged graph at the bottom right of Figure 4 when comparing the selected 12 products by location among the 36 products loaded in the air quenching device according to the present invention, the actual experiment (experiment) and CFD model (simulation) showed cooling results with similar trends.

Therefore, as a result of comparing and verifying the cooling result of the actual air quenching device and the cooling result of the CFD model, the cooling tendency of the product was the same, indicating that the CFD model simulated the air quenching device well.

Test Example 2: Comparison of cooling effects according to different plates

5 is a graph comparing the average temperature of the product after 600 seconds according to the total area of holes and the number of holes, and the results are shown in Table 3 below.

Device Number of holes (pieces) Total area of the hall (m ² ) Average flow velocity of gas through the hole (m/s) Average temperature of the product after 600 seconds (K) Comparative Example 1 (Applied A) - 5.542 (total area of plate) 10.524 612.414 Example 1 (including B) One 2.771 21.049 552.410 Example 2 (with C) 2 2.771 42.099 557.745 Example 3 (including D) 4 2.771 84.197 577.233 Example 4 (with E) 16 2.771 21.049 574.465 Example 5 (with F) 64 2.771 42.099 582.686 Example 6 (with G) One 1.386 84.197 543.285 Example 7 (with H) 2 1.386 21.049 503.421 Example 8 (including I) 4 1.386 42.099 529.298 Example 9 (with J) 16 1.386 84.197 508.633 Example 10 (with K) 64 1.386 21.049 499.916 Example 11 (with L) One 0.693 42.099 538.142 Example 12 (with M) 2 0.693 84.197 405.882 Example 13 (with N) 4 0.693 21.049 439.869 Example 14 (with O) 16 0.693 42.099 441.477 Example 15 (with P) 64 0.693 84.197 456.856

According to Table 3 and FIG. 5, the device according to Comparative Example 1 did not include a separate plate, so cold air was introduced through the entire area of the inlet, and it was found that the average temperature of the product was the highest at about 612K, including a hole pattern. It was found that installing a plate to increase the cooling effect.

In addition, when the device according to Examples 1 to 15 was used, the cooling effect was the best in Example 12, and the average temperature of the product showed a difference of about 206.532 K at most compared to Comparative Example 1, so a plate including a hole pattern I could see the importance of installing (cold air inlet).

Accordingly, the number of holes does not show a tendency, and it can be seen that the smaller the total area of the holes, the better the cooling effect, and it can be seen that the device according to the present invention follows Bernoulli's principle.

Test Example 3: Comparison of gas flow according to different plates

6 is a view simulating the gas flow inside the apparatus according to Comparative Example 1 and Examples 1 to 5. The flow rate inside the device can be inferred from the velocity (m/s) scale bar on the vertical axis, and the surface temperature of the product can be inferred from the temperature (K) scale bar on the horizontal axis.

According to FIG. 6, when the total area of the hole is 2.771 m ² , the flow distribution according to the number of holes can be seen, and it was found that the cooling effect of Example 1 (including B) was the best, and the flow of gas surrounding the product was It was found that the most irregular and turbulent flow was sufficiently induced. In Comparative Example 1 (application of A), the average temperature of the product was 612K, the gas flow was laminar from the inlet to the outlet, and the average temperature of the product in Example 5 (including F) was 612K. and the gas flow was found to be laminar. It is analyzed that laminar flow was observed because turbulence was not induced due to the uniform distribution of holes even when the number of holes increased.

Therefore, it can be seen that the cooling effect is excellent when the gas flow inside the device according to the present invention is turbulent, and it is judged that the number of holes does not significantly affect the cooling effect.

Test Example 4: Optimized design of a plate including a hole pattern

7 to 10 are views showing the structure of the plate according to Preparation Examples 16 to 19. The four dark rectangles here mean the conveyor. In addition, in Table 4 below, the results of comparing the cooling performance according to the use of different plates are described below.

Device plate hole pattern shape Number of holes (pcs) Total area of the hall (m ² ) Average temperature of the product after 600 seconds (K) Example 16 Preparation 16 A flower shape with 8 diameters covering a large-diameter hole 108 0.693 379.946 Example 17 Preparation 17 A regular arrangement of large and small diameter holes 108 0.693 410.795 Example 18 Preparation 18 A shape in which large-diameter and small-diameter holes are randomly arranged. 108 0.693 423.571 Example 19 Preparation 19 Hole pattern of equal size and spacing distribution 108 0.693 468.713

According to FIGS. 7 to 10 and Table 4, although it is difficult to quantify the design of the plate, the case showing the best cooling performance has a diameter of 1/2 or more based on a large circle located in the center as shown in FIG. 7 (Example 16). It was found that the hole in the shape of a small circle formed a repeating pattern.

As mentioned above, although preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various modifications may be made by those of ordinary skill in the art within the scope of the technical spirit of the present invention. It is possible.

Claims (17)

a chamber including an inlet through which gas is introduced, an outlet through which the introduced gas is discharged, and an internal space through which the gas passes to cool the product; and
A plate located at the inlet of the chamber and including a single or a plurality of hole patterns through which the gas passes;
Including air quenching device. According to claim 1,
The air quenching apparatus, characterized in that the gas has a turbulent flow (turbulent flow) in the inner space. According to claim 1,
The air quenching device
Air quenching apparatus according to claim 1, further comprising: a blower located outside the chamber and passing the gas through the hole pattern of the plate and introducing the gas into the inner space. According to claim 1,
The hole pattern includes a single or a plurality of holes,
Air quenching apparatus, characterized in that the shape of the hole comprises at least one shape selected from the group consisting of a circle, a semicircle, an ellipse, and a combination thereof. 5. The method of claim 4,
Air quenching apparatus, characterized in that the shape of the hole comprises a shape of a circle. 5. The method of claim 4,
the hole pattern
first hall; and
a plurality of second holes surrounding the first hole;
Air quenching device, characterized in that it comprises. 7. The method of claim 6,
Air quenching apparatus, characterized in that the number of the second hole is an integer of any one of 2 to 100. 7. The method of claim 6,
The first hole and the second hole are each a circle,
Air quenching apparatus, characterized in that the ratio (D ₂ /D ₁ ) of the diameter (D ₂ ) of the second hole and the diameter (D ₁ ) of the first hole is 0.1 to 1. 9. The method of claim 8,
The ratio (D ₂ /D ₁ ) of the diameter (D ₂ ) of the second hole and the diameter (D ₁ ) of the first hole is 0.2 to 0.7. According to claim 1,
The plate has _a ratio ( _{(A 1 + A 2 ) /} A ₁ ) Air quenching device, characterized in that 1.5 to 15. 11. The method of claim 10,
The plate has _a ratio ( _{(A 1 + A 2 ) /} A ₁ ) Air quenching device, characterized in that 2 to 10. According to claim 1,
Air quenching apparatus, characterized in that the average velocity of the gas after passing through the plate is faster than the average velocity of the gas before passing through the plate. According to claim 1,
Air quenching apparatus, characterized in that the material of the plate is any one selected from the group consisting of steel, stainless steel, iron, aluminum, tin and alloys thereof. According to claim 1,
Air quenching apparatus, characterized in that the outer wall of the chamber is an adiabatic wall (adiabatic wall). According to claim 1,
The air quenching device
Air quenching apparatus, characterized in that it further comprises a conveyor (conveyor) for conveying the product. 16. The method of claim 15,
Air quenching apparatus, characterized in that the conveyor (conveyor) is located in the inner space. 16. The method of claim 15,
The air quenching device
The air quenching apparatus according to claim 1, further comprising a pallet located on said conveyor and for loading said product.

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