KR20170011094A

KR20170011094A - T-type gate valve for frost protection

Info

Publication number: KR20170011094A
Application number: KR1020150103067A
Authority: KR
Inventors: 이병철; 안찬우; 설영진; 김영호; 임지윤; 정영덕
Original assignee: 동아대학교 산학협력단; (주)로프트
Priority date: 2015-07-21
Filing date: 2015-07-21
Publication date: 2017-02-02
Also published as: KR101742194B1

Abstract

The present invention relates to a T-type gate valve for frost protection to prevent frost, which comprises: a housing having a cylindrical hollow portion therein, wherein an inlet passage into which a fluid is inserted and an outlet passage through which a fluid is discharged are respectively formed in a lower portion and an upper portion of a side surface to be interconnected to the hollow portion; a stem extending from the hollow portion of the housing to an outer circumferential surface of the housing, and coupled to be lifted; a disk coupled to a dead end of the stem placed in the hollow portion of the housing, and closing the hollow portion when the stem descends; a temperature sensor measuring a temperature of a fluid in the housing; and a heat emitting member coupled to the disk to be heated when the temperature of the fluid detected by the temperature sensor is less than or equal to a predetermined temperature.

Description

T-TYPE GATE VALVE FOR FROST PROTECTION "

The present invention relates to a T-shaped gate valve capable of preventing freezing, and more particularly, to a T-shaped gate valve capable of preventing freezing of a fluid, including a temperature sensor for detecting the temperature of the fluid and a heating member for generating heat when the detected temperature is lower than a predetermined temperature Type gate valve.

The gate valve is a valve for controlling the flow of the flowing fluid, and is generally used for the purpose of blocking the flow of the fluid.

Among them, the T-shaped gate valve is a valve having a structure in which the inflow and outflow passages of the fluid in the valve body are formed at different heights from each other, and the disc can be closed in the valve body by closing between the inflow passage and the discharge passage .

If such a valve is closed in a state exposed to a cold environment at a low temperature in winter, the internal fluid can not be opened while it is frozen, and the frozen fluid expands and the valve is damaged.

In order to solve this problem, a technique for preventing freezing of fluid in a closed state has been studied, but a commercialized valve is very rare. Especially, a study has not been conducted to prevent freezing of a T-type gate valve.

In addition, if a leak occurs in the valve, it is possible to recognize the leakage only after a large amount of water has leaked, and there is a problem that if leakage occurs, the pipe around the valve is corroded.

In addition, since valves made of metal are corroded with time, there is a problem that the service life is limited.

Patent Document 10-1395292: Temperature sensing unit and freeze prevention valve using the same

Accordingly, the present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a temperature sensor for detecting a fluid temperature and a heating member for generating heat when a detected temperature is lower than a predetermined temperature, The present invention provides a T-shaped gate valve capable of detecting leakages and preventing corrosion.

According to an aspect of the present invention, there is provided a T-shaped gate valve for preventing freeze of a frozen body, comprising: an inlet pipe having a cylindrical hollow formed therein; A housing having a discharge passage communicating with the hollow, respectively; A stem extending from a hollow of the housing to an outer peripheral surface of the housing and coupled to move up and down; A disk coupled to a lower portion of the stem located in the hollow of the housing to close the hollow when the stem is lowered; A temperature sensor for measuring the temperature of the fluid in the housing; And a heating member coupled to the disk and heated when the temperature detected by the temperature sensor is lower than a predetermined value.

The apparatus may further include a closing spring coupled between the housing and the disk to push the disk in a downward direction with elasticity.

In addition, a plurality of recessed stopping grooves are formed on the side surface of the stem in the height direction; A leakage detection sensor for detecting a leakage of water generated at a portion of the outer circumferential surface of the housing where the stem is engaged; a leakage detection sensor coupled to a portion of the outer circumferential surface of the housing where the stem is coupled, And a fixing member for releasing the stem from the fixing groove when the leakage of the liquid is detected through the leakage detection sensor.

The fixing member may include a heating member that is heated when leakage of water is detected by the leakage detection sensor and a bimetal that is coupled with the heating member to release the fixing of the stem due to bending deformation when the heating member is heated .

The apparatus may further include a corrosion-preventing material having a greater ionization tendency than the housing to prevent corrosion of the housing and detachably coupled to a lower end of the disk.

The housing may include a cover coupled with the stem and a body formed with the hollow and detachably coupled to the body so that the corrosion-preventing material can be replaced when the cover is separated from the body .

In addition, a plurality of fastening protrusions protruding outwardly are formed around the upper portion of the body, and a fastening protrusion protruding inwardly in a shape corresponding to the fastening protrusion is formed around a lower portion of the fastening protrusion, And the cover and the body are coupled by assembling the fastening protrusion.

Further, it is preferable to further include a ring-shaped packing coupled to a side surface of the disc to maintain airtightness at the time of closing the hollow, wherein an airtight groove corresponding to the packing is formed on the inner surface of the housing between the inlet and the outlet And is formed by being recessed.

According to the T-shaped gate valve for preventing freezing as described above,

First, the temperature sensor measures the temperature of the fluid, and if the measured temperature is lower than the predetermined temperature, the heating member is heated to raise the temperature of the surrounding structure, thereby preventing the valve from being frozen.

Second, since the closing spring coupled between the housing and the disk pushes the disk in the downward direction, the valve in the open state can be easily closed.

Third, if leakage occurs in the gap between the housing and the stem, leakage can be detected through the leak detection sensor. Since the fixing member fixing the position of the stem is released, the valve automatically closes and a large amount of leakage It is possible to distinguish the fixed release state of the fixing member as the pipe, so that the manager can easily judge that the leak has occurred in the valve.

Fourth, the corrosion of the housing and the disk is prevented because the anti-corrosion material having a higher ionization tendency than the housing is bonded to the lower portion of the disk.

Fifth, since the housing is composed of the cover and the body and can be easily detached and attached, it is possible to easily replace the maintenance and anti-corrosion material of the disk and to easily remove the foreign substances accumulated in the body.

1 is a sectional view showing a closed state of a T-shaped gate valve for preventing freezing according to an embodiment of the present invention;
FIG. 2 is a sectional view showing an open state of a T-shaped gate valve for preventing freezing according to an embodiment of the present invention; FIG.
FIG. 3 is a cross-sectional view illustrating a state in which a lid of a T-shaped gate valve for preventing freezing is separated from a body according to an embodiment of the present invention; FIG.
4 is a perspective view showing a state in which a lid of a T-shaped gate valve for preventing freezing is separated from a body according to an embodiment of the present invention;
FIG. 5A is a partial sectional view showing in detail a fixing member inserted in a stop groove of a T-shaped gate valve for preventing freezing according to an embodiment of the present invention; FIG.
FIG. 5B is a partial sectional view showing in detail a fixing member separated from a stop groove of a T-shaped gate valve for preventing freezing according to an embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, a T-shaped gate valve for preventing freeze of the frost according to an embodiment of the present invention is a valve for controlling the flow of fluid coupled to a conduit, and when the disk 114 descends, the valve is closed, When the valve 114 is lifted and lowered, the valve is opened.

Particularly, it includes an exothermic member 136 for heating the disk 114 and the stem 112, thereby preventing conduits and valves from being frozen in a low temperature environment.

A T-shaped gate valve for preventing freezing of a frost according to an embodiment of the present invention will be described in detail with reference to the drawings. The T-shaped gate valve has a cylindrical hollow 121 formed therein, an inflow path 122 through which fluid flows into a lower side, And a discharge passage 123 through which the fluid is discharged to the upper side of the housing 100, respectively, so as to communicate with the hollow 121. A stem 112 coupled from the hollow 121 of the housing 100 to the outer circumferential surface of the housing 100 so as to move up and down and a stem 112 disposed in the hollow 121 of the housing 100; A temperature sensor 134 coupled to the disk 114 to measure the temperature and a disk 114 coupled to the disk 114 and the stem 112. The temperature sensor 134 is coupled to the disk 114 to close the hollow 121 when the stem 112 is lowered, And a heating member 136 heated when the temperature detected by the temperature sensor 134 is lower than a predetermined temperature.

A cylindrical hollow 121 is formed in the housing 100 in the height direction and an inflow path 122 and a discharge path 123 communicating with the hollow 121 are formed on the side surface.

The inflow path 122 is formed at a lower side of the housing 100 so that the disk 114 can vertically move up and down in the hollow 121 inside the housing 100, Is formed on the side surface of the housing 100. The disc 114 is positioned between the inflow passage 122 and the discharge passage 123, so that the flow of the fluid can be blocked.

The housing 100 is preferably made of a metal material, which is generally used as a valve material.

3 and 4, the housing 100 includes a cover 110 having a stem 112 coupled thereto and a hollow (not shown) coupled to the stem 112 to easily maintain the structure of the disk 114 and the stem 112, 121 formed in the body 120, and are detachably coupled to each other.

The coupling structure of the cover 110 and the body 120 can be implemented by various known methods. However, as shown in the figure, a plurality of fastening protrusions 128 projecting outwardly are formed around the upper portion of the body 120 A fastening hook 118 protruding inward in the form corresponding to the fastening protrusion 128 is formed around the lower portion of the lid 110 so that the fastening protrusion 118 and the fastening protrusion 128 are assembled to the lid 110 And the body 120 are combined with each other.

According to the coupling structure of the embodiment, when the fastening hook 118 of the lid 110 is fitted to a portion where the fastening protrusion 128 is not formed on the upper part of the body 120, and then only the lid 110 is rotated, And the lid 110 and the body 120 are fixed so as not to be separated from each other in the vertical direction.

In order to maintain airtightness in a state where the lid 110 and the body 120 are coupled to each other, a member (not shown) having elasticity may be additionally attached to the lower part of the lid 110 or the upper edge of the body 120.

The stem 112 is configured to move up and down the housing 114 and the disc 114 located in the body 120. The stem 112 is connected to the lower portion of the disc 114, To the housing 100 in a form extending from the hollow 121 of the housing 100 to the outer circumferential surface of the housing 100. [

It is preferable that the clearance is minimized so that the fluid is not leaked to the joint portion between the stem 112 and the housing 100, and sealing can be additionally performed.

The stem 112 of the gate valve is coupled with the housing 100 in a screwed manner and is generally lifted and lowered by rotation. However, the embodiment of the present invention is immediately raised and lowered in the vertical direction. Since the stem 112 that is raised and lowered in the vertical direction is harder to withstand the strong pressure of the fluid that has flowed into the lower portion of the housing 100 than the stem 112 that is generally rotated up and down, It is preferable to apply the present invention to a conduit through which the water is circulated.

A handle 116 for manually moving up and down the stem 112 is formed at an upper portion of the stem 112.

The lower portion of the stem 112 is coupled to a disk 114 that closes the hollow 121 of the housing 100 when the lower portion of the stem 112 descends.

The disk 114 interrupts the hollow 121 of the housing 100 to block the flow.

When the disk 114 descends and is disposed between the inflow passage 122 and the discharge passage 123, the fluid can no longer flow and the valve is closed.

It is preferable that the clearance between the inner wall of the housing 100 and the disc 114 is minimized for the airtightness at the time of closing the valve. In order to further enhance airtightness, a ring-shaped packing 115 is coupled to the side surface of the disk 114, and an airtight groove 115 corresponding to the packing 115 is formed on the inner side surface of the housing 100, (Not shown).

The packing 115 is made of a material having elasticity such as rubber and is compressed between the disk 114 and the inner wall of the housing 100 when the disk 114 is in a position where the airtight groove 125 is not formed When the disk 114 is lowered to the position where the airtight groove 125 is formed, the compressed packing 115 returns to its original shape.

When the valve is closed in a low temperature environment where the temperature falls below 0 ° C, the stagnant fluid is frozen and the valve is opened. To prevent freezing of the fluid, the embodiment of the present invention includes a temperature sensor 134 for measuring the temperature of the disk 114, a temperature sensor 134 coupled to the disk 114 for detecting the temperature detected by the temperature sensor 134 at a predetermined temperature The heating member 136 is heated.

The temperature sensor 134 is coupled to the housing 100 or the disk 114 to measure the temperature of the fluid. The temperature of the fluid can be measured by the temperature sensor 134 being coupled to the inside of the housing 100 or the lower surface of the disk 114 to directly contact the fluid and the temperature of the external surface of the housing 100, The temperature of the fluid may indirectly be determined by measuring the temperature of the housing 100 or the disk 114 and the stem 112 by being coupled to the upper surface of the stem 112 and the stem 112. In the illustrated embodiment, the temperature sensor 134 is disposed on the upper surface of the disk 114 to measure the temperature of the disk 114, so that the temperature of the fluid is indirectly measured.

When the measured temperature is lower than a predetermined value while directly or indirectly monitoring the temperature of the fluid through the temperature sensor 134, power is supplied to the heating member 136 coupled to the disk 114 to be heated. The predetermined value may be 0 ° C at which water begins to freeze.

The heat generated in the heat generating member 136 is transferred to the surrounding structure such as the disk 114 and the housing 100 and the fluid to prevent the valve from being frozen.

When the housing 100 and the stem 112 are frozen, the stem 112 can not move up and down smoothly. If the fluid is water, The heating member 136 may be additionally disposed in the stem 112 and the peripheral housing 100. As shown in FIG.

The heating member 136 is made of a material which is heated when electricity passes through it.

Therefore, the embodiment of the present invention further includes a control device 132 for monitoring the temperature detected by the temperature sensor 134 and a power supply device (not shown) for supplying power, and the temperature sensor 134 and the heat generation The member 136, the control device 132, and the power source device are electrically coupled to each other. The control unit 132 and the power supply unit are general essential components for controlling the temperature sensor 134 and the heat generating member 136, and thus a detailed description thereof will be omitted.

A closing spring for resiliently urging the disk 114 in the downward direction between the housing 100 and the disk 114 in order to increase the pressure that the disk 114 can withstand when the valve is closed and to easily close the valve, (117).

As shown, the closing spring 117 may be constructed of a conventional spiral spring. The upper portion of the housing 100 is fixed to the lower portion of the lid 110 and the lower portion of the housing 100 is fixed to the upper portion of the disk 114 .

The closing spring 117 is basically combined as shown in FIG. 1 and pushes the disk 114 downward from the cover 110. In addition, when an external force for moving the stem 112 upward is applied, it is compressed between the lid 110 and the disk 114 as shown in FIG. The stem 112 and the disk 114 are lowered by the elasticity of the compressed closing spring 117 when the external force of the stem 112 is lifted upward.

A plurality of recessed stopping grooves 113 are formed on the side surface of the stem 112 in the height direction so as to fix the position of the ascending and descending disk 114 in a state where the closing spring 117 is applied, A fixing member 144 for fixing the stem 112 is fixed to the stop groove 113 by inserting a part of the stop groove 113 in the portion where the stem 112 of the outer circumference is coupled.

5A, the fixing member 144 is inserted into the stop groove 113 formed on the side surface of the stem 112 to fix the stem 112 so that the stem 112 can not move up and down.

There may occur a situation in which the fluid leaks to the outside of the housing 100 due to an excessive increase in the pressure of the fluid, poor assembly of the components, aging of the components, and the like. Particularly, the leakage from the valve is mainly represented through the joint between the housing 100 and the stem 112.

Further comprising a leakage detection sensor (142) for detecting a leakage occurring at a portion where the stem (112) of the outer circumferential surface of the housing (100) is engaged so that the leakage of the fluid is blocked and the manager can recognize the occurrence of leakage, The member 144 includes a function of releasing the fixing of the stem 112 by separating from the stopping groove 113 when a leakage is detected through the leakage detection sensor 142.

As shown, the leak detection sensor 142 is preferably provided in the housing 100 to which the stem 112 is coupled to detect leakage.

The leakage detection sensor 142 may be a dedicated sensor capable of detecting a fluid passing through the housing 100. Further, in the case of a fluid through which electric current flows, the leakage detection sensor 142 can be implemented by arranging different electrodes side by side and detecting leakage by causing current to flow when the two electrodes are immersed in the leaked fluid.

When the water leakage sensor 142 detects water leakage, the control device 132 drives the fixing member 144 to be separated from the stop groove 113.

5A and 5B, the fixing member 144 includes a heating member 146 heated when leakage is detected by the leakage detection sensor 142, 146 to release the fixing of the stem 112 due to the bending deformation when the heating member 146 is heated. A clip 148 that is inserted directly into the stop groove 113 to fix the stem 112 and a fixing spring 147 that is engaged with the clip 148 and urges the clip 148 in the direction of the stem 112 ). The bimetal 145 and the clip 148 and the fixing spring 147 are mechanically coupled to each other so that the clip 148 is held by the fixing spring 147 in a state where the bimetal 145 is not deformed, When the bimetal 145 is deformed, the clip 148 is pushed backward and released from the stop groove 113 of the stem 112.

The control device 132 applies a current to the heating member 146 to heat the heating member 146. When the bimetal 145 is deformed by the heat of the heating member 146, The elasticity of the screw fixing spring 147 is released, and the clip 148 is pushed backward. The stem 112 in which the clip 148 is disengaged from the stop groove 113 is moved downward by the elasticity of the closing spring 117 to close the hollow 121. As the hollow 121 of the housing 100 is closed, the leakage occurring at the joining portion between the housing 100 and the stem 112 is stopped, and the manager confirms the clip 148, which is pushed backward, And the fact that it happened.

Like the heating member 136, the heating member 146 is made of a material that is heated when an electric current is applied thereto.

The bimetal 145 is manufactured by superimposing two types of metals having different degrees of expansion and contraction according to a change in the thermal expansion coefficient, that is, a temperature. When the temperature rises, a metal having a larger thermal expansion coefficient is expanded and bent to the opposite side . When the temperature decreases, the bimetal 145 returns to its original shape.

An alloy of nickel (Ni) and iron (Fe) is used as a metal which is not easily inflated. The metal which can be expanded easily is an alloy of nickel, manganese and iron, an alloy of nickel, molybdenum and iron, And alloys of nickel and copper are used.

In order to raise and lower the stem 112 for opening and closing the valve in an environment where no leakage occurs, the clip 148 is forcibly pulled backward to be released from the stop groove 113, have.

The housing 100, the disk 114, and the stem 112 are generally made of a metal containing iron. Since iron corrodes over time, the lifetime of the valve is limited. At the lower end of the disk 114, an anti-corrosion material 152 having a greater ionization tendency than the housing 100 is detachably coupled to prevent corrosion and prolong the service life of the valve.

The ionization tendency is the tendency of a metal to lose electrons and become a cation. Since the ionization tendency is such that the metal is easily oxidized, the metal having a high ionization tendency is more easily oxidized, and the metal having a low ionization tendency does not easily oxidize.

When exposed to water in the presence of a metal having a high ionization tendency and a metal having a relatively low ionization tendency, corrosion of the metal having a low ionization tendency does not occur until all of the metals having high ionization tendency are corroded.

In general, since the valve is made of iron (Fe) as a main material, the corrosion inhibiting material 152 having a higher ionization tendency than the housing 100 is made of potassium K, sodium Na, calcium Ca, magnesium Mg, Zinc (Zn) or the like may be used.

The housing 100 and the disk 114 are not corroded until all the corrosion-resistant material 152 is corroded because the anti-corrosion material 152 is bonded to the lower portion of the disk 114 and directly contacts the fluid.

When the corrosion-preventing material 152 is all corroded, corrosion of the housing 100 and the disk 114 also starts to occur, so it is necessary to replace the corrosion-preventing material 152 periodically. The disc 114 to which the corrosion-preventing material 152 is coupled may be exposed to the outside by separating the lid 110 from the body 120. Thus, by separating the lid 110, the corrosion- Can be replaced.

1 to 3, the anti-corrosive material 152 may be coupled to the disc 114 by being received in a receptacle 150 coupled to the lower portion of the disc 114. At this time, the receptacle 150 has a structure capable of opening one side for facilitating the replacement of the corrosion-preventive material 152, and it is preferable that a gap is formed through which the received corrosion-preventive material 152 is in contact with the fluid Do.

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 exemplary embodiments. It is clear that the present invention can be applied to the same application by appropriately modifying the embodiments. Therefore, the description does not limit the scope of the present invention, which is defined by the limits of the following claims.

100: housing 110: cover
112: stem 113: stop groove
114: Disk 115: Packing
116: handle 117: closing spring
118: fastening hook 120: body
121: hollow 122: inflow path
123: exhaust passage 125: airtight groove
128: fastening protrusion 132: control device
134: temperature sensor 136: heating member
142: Leak detection sensor 144: Fixing member
145: bimetal 146: heating element
147: Fixing spring 148: Clip
150: Housing box 152: Corrosion preventing material

Claims

A housing having a cylindrical hollow formed therein and having an inflow path through which fluid flows into a lower side and a discharge path through which the fluid is discharged from the side surface to communicate with the hollow;
A stem extending from a hollow of the housing to an outer peripheral surface of the housing and coupled to move up and down;
A disk coupled to a lower portion of the stem located in the hollow of the housing to close the hollow when the stem is lowered;
A temperature sensor for measuring the temperature of the fluid in the housing; And
And a heating member coupled to the disk and heated when the temperature detected by the temperature sensor is lower than a predetermined value.

The method according to claim 1,
Further comprising a closing spring coupled between the housing and the disc to push the disc in a downward direction with elasticity.

3. The method of claim 2,
A plurality of recessed stopping grooves are formed on the side surface of the stem in the height direction,
A leakage detection sensor for detecting a leakage occurring at a portion of the outer circumferential surface of the housing coupled with the stem;
Wherein the stem is coupled to a portion of the stem where the stem is coupled with the stop groove of the stem and is inserted into the stop groove to fix the stem up and down. When leakage is detected through the leak detection sensor, Further comprising a fixing member which is detached from the groove and releases the fixing of the stem.

The method of claim 3,
Wherein the fixing member comprises a heating member heated when water leakage is detected by the leakage detection sensor,
And a bimetal coupled to the heating member to release the fixing of the stem when the heating member is heated and bending deformed.

The method according to claim 1,
Further comprising a corrosion inhibiting material having a greater ionization tendency than the housing to prevent corrosion of the housing and detachably coupled to a lower end of the disk.

6. The method of claim 5,
Wherein the housing comprises a lid having the stem coupled thereto and a body formed with the hollow and is detachably coupled to the body so that the corrosion-preventing material can be replaced when the lid is separated from the body. T-type gate valve.

The method according to claim 6,
A plurality of fastening protrusions protruding in the outward direction are formed on an upper portion of the body, and a fastening protrusion protruding inwardly in a shape corresponding to the fastening protrusion is formed around a lower portion of the lid, Wherein the cover and the body are coupled with each other by assembling the cover and the body.

The method according to claim 1,
Further comprising a ring-shaped packing coupled to a side surface of the disc to maintain airtightness during the closing of the hollow,
And an airtight groove corresponding to the packing is formed on the inner side surface of the housing at a portion between the inlet and the outlet so as to prevent freezing.

A housing having a cylindrical hollow formed therein and having an inflow path through which fluid flows into a lower side and a discharge path through which the fluid is discharged from the side surface to communicate with the hollow;
A stem extending from a hollow of the housing to an outer circumferential surface of the housing and coupled to be elevated and lowered and having a plurality of recessed stopping grooves formed in a height direction thereof;
A disk coupled to a lower portion of the stem located in the hollow of the housing to close the hollow when the stem is lowered;
A ring-shaped packing coupled to a side surface of the disc to maintain airtightness during closing of the hollow;
A corrosion resistant material having a greater ionization tendency than the housing to prevent corrosion of the housing and detachably coupled to the lower end of the disk;
A closing spring that is coupled between the housing and the disk and pushes the disk in a downward direction with elasticity;
A temperature sensor for measuring the temperature of the fluid in the housing;
A heating member coupled to the disk and heated when the fluid detected by the temperature sensor is below a predetermined temperature;
A leakage detection sensor for detecting a leakage occurring at a portion of the outer circumferential surface of the housing where the stem is coupled; And
Wherein the stem is coupled to a portion of the stem where the stem is coupled with a stop groove of the stem and is inserted into the stop groove to fix the stem up and down. When leakage is detected through the leak detection sensor, And a fixing member separated from the groove to release the fixing of the stem,
Wherein an airtight groove corresponding to the packing is formed on an inner side surface of the housing at a portion between the inlet and the outlet,
Wherein the fixing member includes a heating member that is heated when water leakage is detected by the leakage detection sensor and a bimetal that is coupled with the heating member and releases bending and deforming when the heating member is heated,
The housing may include a cover coupled with the stem and a body formed with the hollow and detachably coupled to each other. When the cover is separated from the body, the corrosion-preventing material can be replaced,
A plurality of fastening protrusions protruding in the outward direction are formed on an upper portion of the body, and a fastening protrusion protruding inwardly in a shape corresponding to the fastening protrusion is formed around a lower portion of the lid, Wherein the cover and the body are coupled with each other by assembling the cover and the body.