KR200495395Y1 - Duct for hvac insulation - Google Patents

Abstract

The present invention relates to a duct for insulation for air conditioning, and more specifically, a duct including a connection unit is presented, and the air inside the duct is prevented from leaking to the outside through the connection part between the duct and the duct, and the effect of insulation is increased. The purpose of this is to increase the efficiency in the connection process to reduce the fatigue of workers, and to increase the efficiency of the whole process by enabling the process in a narrow place regardless of the conditions of the place.
In addition, in the present invention, the duct 100 is formed in an open form on both sides of a pair of facing each other, and the connection units 200 and 300 are coupled to the open end; The connection units 200 and 300 include a U-shaped flange bar 200 and an h-shaped flange bar 300, each of which is arranged in pairs at the open end portion of two; The pair of the U-shaped flange bar 200 and the h-shaped flange bar 300 are respectively disposed at right angles to the open end of the duct 100; Provides insulation duct for air conditioning.

Description

Insulation duct for air conditioning {DUCT FOR HVAC INSULATION}

The present invention relates to a thermal insulation duct for air conditioning, and more specifically, by attaching the 'U-shaped flange bar' and 'h-shaped flange bar', which are connection units, to the duct to increase the effect of preventing leakage and insulation of the fluid inside the duct. It is about the duct that can be.

A duct means an 'air passage' made of various materials to move or circulate air, and the material of the duct is usually a metal plate material. Duct shapes vary from square ducts to round ducts.

On the other hand, the duct is not only for the purpose of simply moving air, but is often installed for efficiently supplying cooling and heating or for blowing. In particular, it is generally used for the purpose of increasing ventilation efficiency in houses, restaurants, and public facilities.

HVAC (air conditioning system) is an abbreviation of 'Heating Ventilation and Air Conditioning' and means Heating, Ventilation, and Air Cinditioning. The main purpose of the thermal insulation duct for air conditioning is to create a comfortable environment by adjusting the four major elements of air conditioning, temperature, humidity, airflow, and cleanliness, to a state suitable for the purpose.

In general, a flange bar is used for the connection process between ducts, and since these flange bars are mainly made of plastic, they are vulnerable to fire. In addition, the flange bar is mainly composed of a straight jjolldae type, such a straight jjolldae flange bar has a problem in the connection process between the ducts. Specifically, when the difference between the size of the duct and the size of the flange bar is large, there is a problem in that it becomes difficult for the workers to work, and the worker's fatigue and working time increase.

That is, the existing connection unit has difficulty in connecting the duct and the duct in the connection process between the ducts, and also has weaknesses in insulation and leakage prevention.

In addition, the existing air conditioning insulation duct has difficulties in connecting the ducts due to the difference in the thickness of the duct panel and the tolerance between the ducts due to the difference in dimensions between the ducts caused by the cutting process during duct manufacturing This difficult situation causes fatigue to the workers, and also there is a weakness in leak prevention and insulation performance of the duct.

In addition, when the place where the duct is to be installed is narrow, it may be difficult to assemble, which causes fatigue of the workers.

The present invention is to solve the above problems, it proposes a duct including a connection unit, prevents the air inside the duct from leaking to the outside through the connection part between the duct and the duct, and the purpose is to increase the effect of insulation there is.

In addition, an object of the present invention is to reduce the fatigue of workers by increasing the overall efficiency by enabling a sophisticated, quick and easy connection in the connection process for connecting the duct to the duct.

In addition, the present invention aims to increase the efficiency of the entire process by enabling the process in a narrow place regardless of the conditions of the place in the connection process between the ducts.

Objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention that are not mentioned may be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be readily apparent that the objects and advantages of the present invention can be realized by means and combinations thereof indicated in the claims.

In the present invention for achieving this object, the duct 100 is formed in an open form on both sides of a pair of facing each other, and the connection units 200 and 300 are coupled to the open end; The connection units 200 and 300 include a U-shaped flange bar 200 and an h-shaped flange bar 300, and are arranged in pairs at the open end of each of two; The pair of the U-shaped flange bar 200 and the h-shaped flange bar 300 are respectively disposed at right angles to the open end of the duct 100; Provides insulation duct for air conditioning.

In another embodiment of the present invention, the heat insulating material for air conditioning, characterized in that the arrangement structure of the connection units (200, 300) coupled to the open end of the duct (100) is equally disposed on the opposite open end of the duct (100) provide duct.

In another embodiment of the present invention, the arrangement structure of the connecting units 200 and 300 coupled on the open end of one side of the duct 100 is rotated by 180° and is disposed on the opposite open end of the duct 100 It provides a thermal insulation duct for air conditioning, characterized in that.

In another embodiment of the present invention, the arrangement structure of the connection units 200 and 300 coupled on the open end of one side of the duct 100 is disposed on the opposite open end in a 90° rotated form. It provides a thermal insulation duct for air conditioning, characterized in that.

In another embodiment of the present invention, a groove portion is formed on the outer surface of the U-shaped flange bar connection part to seal the duct with silicone or a gasket during the connection process between the ducts. to provide.

In another embodiment of the present invention, there is provided an air conditioning insulation duct, characterized in that a hole is formed in the h-shaped flange bar 300 of the connection unit so that a piece can be processed.

The duct according to the present invention provides a method to further increase the efficiency of the entire connection process by coupling the U-shaped flange bar and the h-shaped flange bar, which is a connecting unit, to the duct.

Such, the present invention has the effect of being able to receive much less influence on the conditions of the duct installation site and the difficulty of connection between the ducts due to the size difference of the ducts in the connection process than the conventional method.

Therefore, the present invention can shorten the working time in the entire process and reduce the fatigue of the workers, so there is an economic effect that can reduce the labor cost for the employer by increasing the efficiency of the work.

In addition, the present invention has the effect of increasing the leakage prevention and insulation performance of the duct itself.

1 is a perspective view showing a duct of the present invention.
Figure 2 is a perspective view showing a connection process between the existing ducts.
3 is a view showing the shape of a U-shaped flange bar, which is a connection unit of the present invention.
4 is a view showing the shape of an h-shaped flange bar, which is a connection unit of the present invention.
5 is a view showing a connection process between the ducts of the present invention.
6 is a view showing a connection process between the ducts of the present invention.
7 is a view showing a connection process between the ducts of the present invention.
8 is a view showing a piece processing process of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement it. The present invention may be implemented in several different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar.

In addition, throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, the present invention will be described in detail using the drawings so that those skilled in the art can implement it.

As shown in FIG. 1 , the heat insulating material duct 100 for air conditioning of the present invention may be configured to have an open shape on both sides of a pair of facing each other.

The connecting units 200 and 300 may be disposed on the open form, and a plurality of ducts may be connected to each other through the connecting unit.

On the other hand, the material of the duct 100 of the present invention is polyisocyanurate (P.I.R), phenolic foam insulation, galvanized steel sheet, stainless steel, steel sheet, mill scale steel sheet, heavy concrete, aluminum, iron sheet, PVC, FRP, and high bar It is characterized in that it comprises one or more selected from the cross.

Due to these material characteristics, the duct 100 can be used for air conditioning purposes, and specifically, it is installed in houses, factories, restaurants, and public facilities to move air, or to efficiently supply heating and cooling and blow air. can do.

In addition, each side of the duct 100 is made of a quadrangle, and the overall shape of the duct 100 is made in the form of a tube. In addition, the size of the duct 100 may be modified.

The connection unit coupled to the duct 100 includes a U-shaped flange bar 200 and an h-shaped flange bar 300 .

In the case of the flange bars 200 and 300, the material of the flange preferably includes at least one selected from aluminum and flame-retardant ABS.

In the case of the existing flange bar, it was mostly composed of plastic. In the case of such a plastic material, there was a problem in stability due to a high risk of fire, and it was easily deformed at high temperature, so it was not preferable to apply it as a stable connection unit.

Accordingly, in the present invention, by changing the material of the flange bars 200 and 300 to include at least one selected from aluminum and flame-retardant ABS, deformation does not occur easily even under high-temperature conditions, and a connection unit with improved stability against external temperature changes. was able to obtain

On the other hand, it is preferable that the U-shaped flange bar 200 and the h-shaped flange bar 300 are inserted into the open end of the duct 100 so as to be disposed in a right angle structure, respectively.

Specifically, in the present invention, at the open end of the h-shaped flange bar 300 facing both sides of the duct 100, any one corner portion and the corner closest to the any one corner portion It is characterized in that the U-shaped flange bar 200 is also coupled to the other corners and arranged in a right angle structure to be coupled to each other and arranged in a right angle structure.

As above, when the h-shaped flange bar 300 is arranged in a right angle structure on the two most adjacent corners, and the U-shaped flange bar 200 is also arranged in a right angle structure on the other corners, the connection process between the ducts is performed. It has the advantage of being able to proceed much more easily.

Specifically, the reason that the connection process between the ducts becomes easier is as follows.

First, the connection process between the ducts proceeds in such a way that the h-shaped flange bar 300 is coupled to the U-shaped flange bar 200 on the U-shaped flange bar as described in FIGS. 5 to 7 .

At this time, in the case of the conventional duct, as shown in FIG. 2 , an h-shaped flange bar is formed on each corner of the open end, and a U-shaped flange bar is formed on all corners of the open end of the other duct to be connected. As a result, it was possible to connect the duct to the duct in such a way that the face of the U-shaped flange bar was fitted onto the face of the h-shaped flange bar on four sides.

On the other hand, when duct and duct are connected in the same way as above, the duct connection process can only proceed in one direction, so it is very difficult to carry out the connection process in a narrow place. , there was a problem that the connection process was impossible because it was impossible for the surface made of the U-shaped flange bar to enter onto the surface made of the h-shaped flange bar.

In addition, it is necessary to finely adjust the connection process so that the connection surfaces between the ducts enter a completely overlapped state, and the connection process takes a long time, which increases the fatigue of the workers.

On the other hand, according to the duct of the present invention, the h-shaped flange bar 300 is disposed in a right angle structure at two adjacent corners on the open end of the duct, and also the U-shaped flange bar 200 is disposed in a right angle structure at the other two corners. do. Such an arrangement structure is shown in Figs. 5 to 7, and through this arrangement structure, the duct and the duct can be easily connected in such a way that the operator slides the duct to be connected.

When the ducts are connected in the above manner, the duct can be assembled in various directions as well as in one direction, so the connection process can be easily carried out even in a relatively narrow space, and even if there is a slight tolerance in the size of the panel constituting the duct , there is an advantage that the connection process becomes possible.

In addition, it is possible to reduce the time required for the connection process, and by combining the connection units 200 and 300 containing one or more metal materials such as aluminum and flame-retardant ABS to the duct, the area in contact with the air inside the duct is minimized, thereby increasing the insulation, By forming a protrusion on the connection unit, there is an advantage in that the air inside the duct is prevented from leaking to the outside, thereby improving the leak prevention property.

In addition, as shown in FIG. 6 , the structure of the connecting units 200 and 300 in which the structure of the connecting units 200 and 300 disposed on the open end of one side of the duct 100 is rotated by 180° is the remaining Structures on one side of the open end can also be used.

If the duct structure in which the connection units 200 and 300 are arranged in the upper and lower portions rotated 180° is used, when workers want to connect two or more ducts in a row, they can quickly connect the ducts by sliding in one direction. because there is

As shown in Figure 2, the existing duct can connect the duct only in one direction, but the duct connection structure of the present invention has the advantage of increasing the operator's convenience and shortening the process time because it can be combined in various directions. .

When the connection process is carried out through the slide-type process as described above, it is not necessary to finely adjust the connection process so that the connection surfaces between the ducts enter a completely overlapped state, so the time consumed in the connection process can be significantly reduced. It can reduce operator fatigue as well as increase the efficiency of the entire process.

The structures of the U-shaped flange bar 200 and the h-shaped flange bar 300 used in the present invention are as shown in FIGS. 3 and 4 .

3, a U-shaped flange bar connection protrusion 231 may be formed on the inner surface of the U-shaped flange bar connection part, and a U-shaped flange bar short side projection 231 is formed on the inner surface of the U-shaped flange bar end side part ( 211) may be formed, and a U-shaped flange bar long side projection 221 may be formed on the inner surface of the long side portion of the U-shaped flange bar.

It is preferable that the short side projections 211 and the long side projections 221 of the U-shaped flange bar are formed in a sawtooth shape in which an inclined portion protrudes in an oblique direction toward the connection portion, and the U-shaped flange bar The connecting protrusion 231 may be formed in a form in which an end is sharply terminated.

These projections, in coupling the connection unit to the duct, by making the connection between the connection unit and the duct strong, it is possible to improve the coupling force between the duct and the connection unit to prevent the connection unit from being separated from the duct arbitrarily. .

In addition, the protrusion has an effect of preventing the air inside the duct from leaking to the outside by blocking the flow of air.

On the other hand, the length of the short side projection 211 and the long side projection 221 is preferably formed to be 5 to 10 mm.

If the length of the protrusion is formed to be shorter than 5 mm, frictional force with the duct is not sufficiently generated, so that the fixing force between the duct and the connecting unit is not significantly increased.

On the other hand, when the length of the protrusion is formed to be greater than 10 mm, the pressure applied to the duct becomes strong, and there is a possibility that the duct may be damaged, which is not preferable.

In addition, a groove portion may be formed on the outer surface of the U-shaped flange bar connection portion.

In particular, in the case of the groove portion, it is preferable to have a height of 0.5 to 1 mm.

When the groove is cut as above, in the connection process between the ducts, silicone or gaskets can be inserted so that accurate assembly without gaps can be performed.

In addition, in the case of the U-shaped flange bar 200, it is preferable that the height of the U-shaped flange bar short side portion and the U-shaped flange bar long side portion are different from each other.

If the height of the short side and the long side is the same as each other, it is not easy to couple the connection unit to the open end of the duct, and heat loss inside the duct and air leakage inside the duct may occur. , it is preferable that the height of both surfaces of the connection unit is formed to be different.

4 is a side view of the h-shaped flange bar 300 which is the connection unit shown in FIG. 1 .

Like the U-shaped flange bar 200, the h-shaped flange bar 300 may have an h-shaped flange bar connection protrusion 331 formed on the inner surface of the h-shaped flange bar connection part, and the h-shaped flange bar end An h-type flange bar short protrusion 311 may be formed on the inner surface of the side portion, and an h-type flange bar long side protrusion 321 may be formed on the inner surface of the long side h-type flange bar.

It is preferable that the short side projections 311 and the long side projections 321 of the h-shaped flange bar are formed in a sawtooth shape in which an inclined portion protrudes in an oblique direction toward the connection part, and the h-shaped flange bar The connecting protrusion 331 may be formed in a form in which an end is sharply terminated.

As described above, since the protrusion serves to firmly fix the coupling between the duct and the connecting unit, in the case of the present invention due to the above protrusion, the coupling force between the duct and the connecting unit can be significantly improved.

In addition, the protrusion has an effect of preventing the air inside the duct from leaking to the outside by blocking the flow of air.

On the other hand, the length of the short side projection 311 and the long side projection 321 is preferably formed to be 5 to 10 mm.

If the length of the protrusion is formed to be shorter than 5 mm, frictional force with the duct is not sufficiently generated, so that the fixing force between the duct and the connecting unit is not significantly increased.

On the other hand, when the length of the protrusion is formed to be greater than 10 mm, the pressure applied to the duct becomes strong, and there is a possibility that the duct may be damaged, which is not preferable.

In addition, in the case of the h-shaped flange bar 300 , it is preferable that the height of the short side of the h-shaped flange bar and the long side of the h-shaped flange bar are different from each other, similar to the U-shaped flange bar 200 .

In the case of the short side, by making the length shorter than the long side, the contact area with air is reduced to prevent heat loss. .

In addition, in the case of the h-shaped flange bar 300, the h-shaped flange bar protrusion is assembled with the U-shaped flange bar by adding a tolerance to the long side of the h-shaped flange bar unlike the conventional flange bar that is in a straight line with the lower part on the upper side. can be made easier. This is a major configuration in facilitating the connection process between the ducts.

In addition, as shown in FIG. 8, during the connection process between the ducts, the joint portion is sealed by sealing the groove portion of the U-shaped flange bar and the connection surface of the h-type flange bar, which is a portion in contact with the groove portion, with a sealing material such as gasket and silicone. can do.

On the other hand, it is possible to seal only one part of the groove part of the U-shaped flange bar or the connection surface of the h-shaped flange bar with milling material, but sealing both the U-shaped flange bar groove part and the connecting part of the h-shaped flange bar reduces the fastening force between the ducts. It is most desirable to seal both parts in order to prevent leakage of fluid and loss of heat because it further increases. (See Fig. 8)

In addition, after sealing the gasket and silicone, a piece treatment is performed on the protrusion of the h-shaped flange bar 300 so that the duct and the duct can be more firmly fixed. This is a configuration that plays a major role in increasing the fastening force between the ducts.

The short side portions of the connection units (200, 300) are in contact with the inner surface of the duct (100), and the long side portion of the connection unit is in contact with the outer surface.

When assembling the connecting units 200 and 300 to the duct 100 as described above, workers can easily couple the connecting units 200 and 300 to the duct 100, and the duct 100 and the connecting units 200 and 300 ) and can increase the strength of the duct 100 itself, heat insulation, and leak prevention properties.

In the case of the conventional insulation duct for air conditioning, there are no emboss or protrusions formed on the surface of the duct, so there is a weakness in that heat loss and leakage occur between the places where the inside of the embossed and flat connecting unit come into contact with each other.

On the other hand, to solve the problem in the existing duct, by forming a protrusion in the connection units 200 and 300, the air in the duct 100 plays a role in interfering when going out from the inside to the heat loss and leakage of the duct 100. can prevent

In addition, in the connection process between the ducts, since the projections of the U-shaped flange bar 200 of the duct 100 and the projections of the h-shaped flange bar 300 have a vertically inverted shape, frictional force is generated to improve the bonding force. Desorption between ducts can be prevented.

By using the duct of the present invention, the h-shaped flange bar 300 and the U-shaped flange bar 200 are connected without flange deformation in the state in which the connection units 200 and 300 are coupled on each corner of the duct 100. It is possible to perform a connection process between the duct and the duct connecting the duct by connecting the duct. When performing the connection process, it is preferable to finish the flange bar with a common mill material such as silicone, and then perform additional piece processing to prevent air from leaking to the outside in advance.

Hereinafter, specific examples are provided to help the understanding of the present invention. However, the following test 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 1>

The material of the duct is characterized in that it contains at least one selected from polyisocyanurate (P.I.R) and phenolic foam insulation, and the material of the flange bar at the open end of the duct includes at least one selected from aluminum and flame-retardant ABS The connecting units (U-shaped flange bar, h-shaped flange bar) are coupled to each other, but the connecting units are arranged in pairs at each of the open end portions in pairs so that they are arranged in a right angle structure.

In addition, the arrangement structure of the connecting unit disposed on the open end of the duct is made to have the same structure on the opposite open end,

The duct and the duct configured in the same way as the duct were connected so that the h-shaped flange bar and the U-shaped flange bar were in contact with each other, so that the connecting process between the ducts was performed.

Thereafter, after connecting 10 ducts through the duct-to-duct connection process as described above, the time required for duct connection, leakage rate and heat loss rate of the connected ducts were measured.

<Example 2>

In the connecting unit coupled to the open end of the duct, the arrangement structure of the connecting unit disposed on the open end of the duct is rotated by 180° on the opposite open end.

Others were carried out in the same manner as in Example 1.

<Example 3>

In the connecting unit coupled to the open end of the duct, the arrangement structure of the connecting unit disposed on the open end of the duct is rotated by 90° on the opposite open end.

Others were carried out in the same manner as in Example 1.

<Comparative Example 1>

In the same manner as in the conventional duct, an experiment was conducted under the same conditions as in Example 1, except that h-shaped flange bars were joined to all corners on the open end of the duct, and U-shaped flanges were joined to all corners on the opposite open end. proceeded.

The test results performed under the conditions of Examples 1, 2, 3 and Comparative Example 1 are shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Process required time 28 minutes 25 minutes 32 minutes 1 hour 42 minutes Leakage rate (%) 1.95% 1.99% 1.898% 5.12% Heat loss rate (%) 5.89% 5.85% 5.89% 6.2%

From the above results, it is possible to confirm the result values of the process required time, leakage rate, and heat loss rate in each Example and Comparative Example 1. The measurement method and calculation method of each result value are as follows. In the case of the process required time, it is the time required to connect 10 ducts. The average value of time is reported.

In the case of the leak rate, the air volume (leakage) of the press-in blower was measured at this time while maintaining the test pressure by putting air in the duct with the blower of the leak tester in a sealed state. The value was calculated.

In the case of heat loss rate, the outlet temperature of the duct and the surface temperature in the middle part of the duct were measured through a thermal imaging camera while hot air of 60 to 65 ° C was injected to one side of the duct for 5 minutes, and in the middle part of the duct The value of the temperature of the outlet compared to the temperature of was calculated.

Below, we will compare the results in detail based on Table 1.

In the case of the process required time, it took 1 hour and 42 minutes in Comparative Example 1 of the same method as the existing duct, but Examples 1 to 3 according to the present invention were 28 minutes, 25 minutes, and 32 minutes, respectively, approximately 1 hour compared to Comparative Example 1 It can be seen that the process time of about 10 minutes was significantly reduced.

Similarly, in the case of leakage rate, Comparative Example 1 gave a result value of 5.12%, but in Examples 1 to 3, respectively, 1.95%, 1.99%, 1.898%, 3.17%p, 3.13%p, 3.222%p fluid compared to Comparative Example 1 It can be confirmed that the leakage also occurred less.

In addition, in the case of the heat loss rate, 6.2% of heat was lost in Comparative Example 1, but the heat loss rate of the duct of the present application was 5.89%, 5.85%, and 5.89%, respectively, which significantly improved the process time compared to Comparative Example 1 according to the existing duct. Although it was shortened, it can be confirmed that the heat loss was maintained although it was weak, and it was confirmed that the heat loss occurred relatively little.

In addition, it can be confirmed that, in particular, Example 2 is the most effective in all the results.

It can be seen that the conventional duct takes a particularly long process time, and heat loss to the outside through the connection unit and the duct occurs relatively often, and fluid leakage also occurs a lot.

On the other hand, when the duct of the present invention is used, the time required for the connection process between the ducts can be greatly reduced, and it can be seen that the leak prevention property and the heat insulation property are also excellent.

100: duct
200: U-shaped flange bar
211: U-shaped flange bar one side projection
221: U-shaped flange bar long side projection
231: U-shaped flange bar connection projection
300: h-shaped flange bar
311: h-shaped flange bar one side projection

Claims (6)

In the insulation duct 100 for air conditioning,
The duct 100 is made in an open form on both sides of a pair of facing each other, and the connection units 200 and 300 are coupled to the open end,
The connection units 200 and 300 include a U-shaped flange bar 200 and an h-shaped flange bar 300, each of which is arranged in pairs at the open end of each two,
The pair of the U-shaped flange bar 200 and the h-shaped flange bar 300 are respectively disposed at right angles to the open end of the duct 100,
Insulation duct for air conditioning.
According to claim 1,
The arrangement structure of the connecting units (200, 300) coupled on the open end of the duct (100) is characterized in that the same arrangement is formed on the opposite open end of the duct (100)
Insulation duct for air conditioning.
According to claim 1,
The arrangement structure of the connecting units (200, 300) coupled on the open end of one side of the duct (100) is rotated by 180°, characterized in that it is disposed on the opposite open end of the duct (100)
Insulation duct for air conditioning.
According to claim 1,
The arrangement structure of the connection units (200, 300) coupled on the open end of one side of the duct (100) is rotated by 90°, characterized in that it is disposed on the opposite open end of the duct (100)
Insulation duct for air conditioning.
According to claim 1,
A groove is formed on the outer surface of the U-shaped flange bar connection part so that it can be sealed with silicone or a gasket during the connection process between the ducts.
Insulation duct for air conditioning.
According to claim 1,
In the connection process between the ducts, characterized in that a piece processing is performed on the h-shaped flange bar 300
Insulation duct for air conditioning.

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