KR20170100089A - Gasket for air duct - Google Patents

Gasket for air duct Download PDF

Info

Publication number
KR20170100089A
KR20170100089A KR1020160021880A KR20160021880A KR20170100089A KR 20170100089 A KR20170100089 A KR 20170100089A KR 1020160021880 A KR1020160021880 A KR 1020160021880A KR 20160021880 A KR20160021880 A KR 20160021880A KR 20170100089 A KR20170100089 A KR 20170100089A
Authority
KR
South Korea
Prior art keywords
gasket
flange
air duct
band
contact
Prior art date
Application number
KR1020160021880A
Other languages
Korean (ko)
Inventor
이순
조동준
Original Assignee
(주)대양기연
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by (주)대양기연 filed Critical (주)대양기연
Priority to KR1020160021880A priority Critical patent/KR20170100089A/en
Publication of KR20170100089A publication Critical patent/KR20170100089A/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/02—Ducting arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/02—Sealings between relatively-stationary surfaces
    • F16J15/021—Sealings between relatively-stationary surfaces with elastic packing
    • F16J15/022—Sealings between relatively-stationary surfaces with elastic packing characterised by structure or material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/02—Sealings between relatively-stationary surfaces
    • F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
    • F16J15/10—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing
    • F16J15/102—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing characterised by material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/02—Sealings between relatively-stationary surfaces
    • F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
    • F16J15/10—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing
    • F16J15/104—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing characterised by structure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L17/00—Joints with packing adapted to sealing by fluid pressure
    • F16L17/06—Joints with packing adapted to sealing by fluid pressure with sealing rings arranged between the end surfaces of the pipes or flanges or arranged in recesses in the pipe ends or flanges
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L23/00—Flanged joints
    • F16L23/16—Flanged joints characterised by the sealing means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L23/00—Flanged joints
    • F16L23/16—Flanged joints characterised by the sealing means
    • F16L23/18—Flanged joints characterised by the sealing means the sealing means being rings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/02—Ducting arrangements
    • F24F13/0209—Ducting arrangements characterised by their connecting means, e.g. flanges

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Duct Arrangements (AREA)
  • Flanged Joints, Insulating Joints, And Other Joints (AREA)
  • Gasket Seals (AREA)

Abstract

The present invention relates to a gasket for connecting an air duct.
Accordingly, the present invention is directed to an overlay gasket or band-fit gasket for improving the connection and installation of circular ducts used in air conditioning and ventilation systems of a ventilation system, It is easy to install and easy to put on or insert, but it is formed to be able to secure a strong sealing force, which greatly improves the airtightness compared to the previous one. do.

Description

Gasket for air duct connection {Gasket for air duct}

The present invention relates to a gaskets or band-fit gaskets for improving connection and installation between circular ducts used in air conditioning and ventilation systems of ventilation systems, which gaskets are simply put on or fitted to the flanges of the circular ducts It is possible to secure a strong sealing force, thereby greatly improving the airtightness against the conventional air conditioner. In addition, the air duct connection For example.

Generally, a dry air duct system is installed on the side of the kitchen and the bathroom side in a high-rise building such as an apartment in order to normally exhaust the odor generated from the kitchen side and the bathroom side.

These dry air duct systems connect the air ducts using PVC or Galbarium (aluminum galvanized) materials to each floor, allowing them to be natural or forced exhaust from the roof tops .

As shown in FIG. 6, the conventional dry air duct system includes a plurality of air ducts 1 connected in a direction directly below the building, connected to one side of the air duct, The saddle 4 is installed to be fixed to the bladder 3 and the uppermost layer of the air duct is provided with an exhaust pier plate 5 and an exhaust fan 6 is installed above the exhaust pier 5 .

At this time, the air duct is connected and fixed by a plurality of air ducts 1 and 2 by a V-band 10 or a coupling, and an interlayer part (concrete layer) through which the air ducts 1 and 2 pass, The lower air duct 2 having passed through the sleeve 7 is seated on the upper portion of the sleeve 7 by using a separate fixed support member 20 so that the lower air duct 2 The lower air duct 2 is prevented from sagging and the space between the lower air duct 2 and the sleeve 7 is cut off so that smoke and flames are transmitted to the upper layer when a fire occurs .

In order to construct the conventional dry air duct system, auxiliary materials such as a V-band 10 for connecting a plurality of air ducts 1 and 2 are inevitably required. In such a conventional V-band 10 Is engaged with the flange of the upper and lower divided air ducts so that one side thereof serves as a hinge and the other opened side is fastened by bolts and nuts or the like so that silicone is filled in the inside of the V band.

As described above, conventionally, it is necessary to manufacture a small amount of subsidiary material for connecting the air duct formed between the upper and lower ends, and there is a problem that the workability is lowered, the cost of construction is increased, the airtightness and the productivity are lowered It is true.

In other words, the conventional V-band fastening method, which has been used for a long time, is excellent in the bonding strength, but it is hard to confirm the state by fixing the internal silicon material to the arbitrary application of the operator, and as a result, the airtightness is generally poor It is true.

In addition, there is a possibility that deformation may occur due to external influences after the operation, and the degree of airtightness due to the curing phenomenon of silicon may deteriorate over a long period of time, and development of a reliable packing method is urgently required.

1. Korean Utility Model Registration No. 20-0459694 (Registered on April 02, 2012)

It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide an envelope-type gasket or band-fitting gasket for improving the connection and installation of circular ducts used in air conditioning and ventilation systems of a ventilation system, The gasket can be easily put on or fitted to the flange of the circular duct to ensure easy and convenient operation, but it is formed to secure a strong sealing force so that the airtightness against the previous one is greatly improved, and also the sealing reliability And a gasket for connection to an air duct.

That is, the present invention provides a new connection method combining a V-band system and a flange gasket system and adopting a gasket system having a stable airtightness inside a V-band robust detachment structure to provide a new connection method .

Accordingly, the present invention provides an improved connection method in which airtightness is further enhanced to prevent leakage. In the conventional V-band method, a structure in which silicon is thinly coated on the outer circumferential surface of a flange (undercutter) The present invention is directed to an improved connection method for attaching an EPDM gasket between a V-band and a V-band, thereby achieving a packing airtight effect of pressing on a wide surface.

In addition, the present invention improves an unstable working mind by using a standard type gasket. In the conventional method, since it is difficult to confirm the quality, it is difficult to check the quality of the worker or the conscience The purpose of the improvement is fundamental.

It is another object of the present invention to develop a gasket of a structure and material which is easy to install and does not fall off. It is a structure in which a gasket is easily mounted using a conventional bottom cutter as a flange, And is made of elastic material.

In addition, the present invention improves airtightness by corresponding to a partial floating deformation space of a coupling surface by a plurality of protruding blades on the outer surface of the gasket, wherein a plurality of protruding type blades And to improve the airtightness by absorbing unevenness of unevenness of the granular straight pipe or uneven irregularities of the undercut surface or partial floating phenomenon due to spatio-temporal deformation.

In addition, the present invention improves workability by one-touch fastening of a V-band than a conventional flange gasket connection method. In the conventional flange gasket connection method, in order to solve the problem of leaking due to an intermediate lifting phenomenon depending on the interval between fastening bolts, The bolt must be fastened. This requires troublesome work. The object of the present invention is to provide a V-band that can be completed by a one-touch fastening of the V-band so that a reasonable work can be accomplished.

In order to achieve the above-described object, the present invention provides a method of manufacturing a circular duct (10), which is formed by rubber, silicone or elastic material, and which is inserted into a flange (11) 11: a bottom cutter), the insertion holder 100 having a longitudinal cross-sectional shape of '⊂' shape to form a ring band shape; A contact portion 200 protruding from one side or both sides of the upper and lower ends of the outer periphery of the insert holder 100 to contact the flange 11-1 of the neighboring circular duct to induce the double airtightness; .

Accordingly, the present invention of the above embodiment is formed by either the rib 210 protruded from the contact part 200, or the wing-shaped or wavy-shaped curved shape 220.

In the meantime, according to another embodiment of the present invention, as shown in FIG. 1, the rear ribs 11 and 11-1 of the circular duct 10, which are vertically abutted with each other, A fillet holder 300 is formed in one side of the flange 11 so as to be in close contact with the upper and lower surfaces of the flanges 11 and 11-1, Wow; A contact blade 400 extending integrally to an end of the fill groove 310 of the fill holder 300 and extending in a direction orthogonal to the flange so as to be in close contact with an outer circumferential surface of the circular duct, .

In another embodiment of the present invention, the fill holder 300 further comprises a folding groove 320 and a wing-type airtight pad 330 on either or both of the upper and lower surfaces.

In addition, according to the present invention, the gasket is fastened to the flange 11 of the circular duct 10, and the binding V band 500 is joined to the outer circumferential surface of the flange 11 to pressurize or press the super- So that the fastening method is performed.

As such, the present invention relates to a gasket or band-fit gasket for overlaying which improves the connection and installation of circular ducts used in air conditioning and ventilation systems of a ventilation system, It is possible to secure easy and convenient workability by inserting or inserting, but it is formed so as to secure a strong sealing force, thereby greatly improving the airtightness compared to the past, and also has a high sealing reliability and an excellent convenience of operation even when a non-expert is working.

That is, the present invention has a new concept of connecting a V-band system and a flange gasket system, and adopts a gasket system having a stable air-tightness inside a V-band robust detachment structure.

Accordingly, the present invention provides an improved connection method in which airtightness is further enhanced to prevent leakage. In the conventional V-band method, a structure in which silicon is thinly coated on the outer circumferential surface of a flange (undercutter) The EPDM gasket is mounted between the V-band and the V-band, and then the V-band is tightened to compress the large surface.

In addition, the present invention improves an unstable working mind by using a standard type gasket. In the conventional method, since it is difficult to confirm the quality, it is difficult to check the quality of the worker or the conscience There is an effect of improving originally.

In addition, the present invention aims to develop a gasket having a structure that is easy to install and does not fall off as a flexible material, and it is an effect that a gasket can be easily mounted using a conventional bottom cutter as a flange, have.

In addition, the present invention improves airtightness by corresponding to a partial floating deformation space of a coupling surface by a plurality of protruding blades on the outer surface of the gasket, wherein a plurality of protruding type blades And the airtightness is improved by absorbing uneven irregularities on the eccentricity of the granular straight pipe, undulating unevenness on the undercut surface, or partial floating phenomenon due to spatio-temporal deformation.

In addition, the present invention improves workability by one-touch fastening of a V-band than a conventional flange gasket connection method. In the conventional flange gasket connection method, in order to solve the problem of leaking due to an intermediate lifting phenomenon depending on the interval between fastening bolts, The bolts must be fastened. This requires troublesome work. This is effective in that the work is completed and a reasonable work can be accomplished only by one-touch fastening of the V-band.

FIGS. 1 and 2 illustrate an embodiment of the present invention in which the longitudinal section of the insert holder of the gasket is formed in the shape of '⊂'
Figure 3 is another example of Figures 1 and 2,
FIGS. 4 to 5 are views showing another embodiment of the present invention in which the longitudinal section of the filler holder of the gasket is formed in the shape of '<'
6 is a side sectional view schematically showing the construction of a general dry air duct system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings.

First, as shown in FIGS. 1 to 3, the gasket of the present invention is roughly composed of an insertion holder 100 and a contact portion 200 as one embodiment.

The insertion holder 100 is made of rubber, silicone or elastic material. The insertion holder 100 is inserted in correspondence with the flange 11 of the circular duct 10 and is in contact with the rear surface of the flange 11 (undercut) And a fitting groove 110 is formed on one side so as to be in close contact with the upper and lower surfaces.

The contact portion 200 protrudes from one side or both sides of the upper end and the lower end of the outer circumference of the insert holder 100 to be brought into contact with the flange 11-1 of the neighboring circular duct, do.

Accordingly, the present invention of the above embodiment is formed by either the rib 210 protruded from the contact part 200, or the wing-shaped or wavy-shaped curved shape 220.

At this time, the ribs are formed so that at least two of at least two of the ribs protrude from the flange circumferential surface of the circular duct at regular intervals, which are formed in one direction by the elasticity when the flanges are abutted with each other.

In addition, the bent shape is formed in an embossed shape of a bone and an acid shape, and is formed so as to maintain or secure a multi-stage airtightness to the flange and the V-band tight contact portion.

Meanwhile, the gasket of the present invention is composed of a filler holder 300 and a contact blade 400 as an alternative embodiment.

At this time, the filling holder 300 is made of rubber, silicone, or elastic material, and is inserted in correspondence with the protruding ribs 11 and 11-1 of the circular duct 10, A cover 310 is formed on one side of the flanges 11 and 11-1 so as to be in close contact with the upper and lower surfaces of the flanges 11 and 11-1.

The contact vane 400 is integrally formed with the end of the fill groove 310 of the fill holder 300 so that the contact vane 400 extends in a direction orthogonal to the flange so as to be in close contact with the outer circumferential surface of the circular duct, do.

That is, the contact blade is formed in a band shape having a large cross-sectional area, and is formed so as to greatly improve airtightness by being closely attached to the outer circumferential surface of the circular duct.

In another embodiment of the present invention, the fill holder 300 further comprises a folding groove 320 and a wing-type airtight pad 330 on either or both of the upper and lower surfaces.

At this time, the folding grooves are formed so that when the contact wing is wide and difficult to insert into the flange, one side is lifted up to be folded, and then, when the corresponding other flange faces, the folding groove is rewound so that the normal tightening can be easily performed. At this time, it is preferable that the folding grooves are formed in an arc shape having one side opened.

At this time, the airtight pad is formed to abut the inner periphery of the V-band 500 to secure airtightness.

In addition, according to the present invention, the gasket is fastened to the flange 11 of the circular duct 10, and the binding V band 500 is joined to the outer circumferential surface of the flange 11 to pressurize or press the super- So that the fastening method is performed.

In other words, the present invention is capable of maintaining airtightness even without the conventional silicon filling, and is formed so as to be capable of binding with a double or triple structure (gasket and V-band) on the inside and outside of the connecting portion of the circular duct.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

100 ... insertion holder 110 ... fitting groove
200 ... contact portion 210 ... rib
220 ... flexure type 300 ... fill holder
310 ... Covering groove 320 ... Folding groove
330 ... airtight pad 400 ... contact wing
500 ... V band

Claims (5)

(11) (bottom cutter) of the circular duct (10) so as to be in contact with the upper and lower surfaces of the flange (11) 110, which are formed in a shape of '⊂' to form a ring band shape;
A contact portion 200 protruding from one side or both sides of the upper and lower ends of the outer periphery of the insert holder 100 to contact the flange 11-1 of the neighboring circular duct to induce the double airtightness;
And a gasket for connecting an air duct. The gasket for connecting an air duct according to claim 1, wherein the contact portion (200) is formed of a protruding rib, a wing shape, or a wavy shape. (11, 11-1) of the circular duct (10) which is in contact with the upper and lower sides of the flange (11, 11-1) : A filler holder 300 having a cover 310 formed at one side thereof so as to be in close contact with the upper and lower surfaces and having a longitudinal profile of '<' shape to form a ring band;
A contact blade 400 extending integrally to an end of the fill groove 310 of the fill holder 300 and extending in a direction orthogonal to the flange so as to be in close contact with an outer circumferential surface of the circular duct,
And a gasket for connecting an air duct. 4. The air duct connecting gasket according to claim 3, wherein the fill holder (300) further comprises a folding groove (320) and a wing airtight pad (330) on one or both of the upper and lower surfaces . The gasket as claimed in any one of claims 1 to 4, wherein the gasket is fastened to the flange (11) of the circular duct (10), and the binding V band (500) is fastened to the outer circumferential surface thereof, And a gasket for connecting an air duct.
KR1020160021880A 2016-02-24 2016-02-24 Gasket for air duct KR20170100089A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020160021880A KR20170100089A (en) 2016-02-24 2016-02-24 Gasket for air duct

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020160021880A KR20170100089A (en) 2016-02-24 2016-02-24 Gasket for air duct

Publications (1)

Publication Number Publication Date
KR20170100089A true KR20170100089A (en) 2017-09-04

Family

ID=59924147

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020160021880A KR20170100089A (en) 2016-02-24 2016-02-24 Gasket for air duct

Country Status (1)

Country Link
KR (1) KR20170100089A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101952391B1 (en) * 2018-06-05 2019-02-27 (주)대양기연 Flexible V-band for Duct and it's construction method
KR102189068B1 (en) * 2019-08-09 2020-12-10 (주)대양기연 Sealing method for chimney with nonflammable fiber O-ring and silicon sheet gasket
KR20210141387A (en) * 2020-05-14 2021-11-23 주식회사 원방테크 Divided region changeable rotor magic box, and dehumidification system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101952391B1 (en) * 2018-06-05 2019-02-27 (주)대양기연 Flexible V-band for Duct and it's construction method
KR102189068B1 (en) * 2019-08-09 2020-12-10 (주)대양기연 Sealing method for chimney with nonflammable fiber O-ring and silicon sheet gasket
KR20210141387A (en) * 2020-05-14 2021-11-23 주식회사 원방테크 Divided region changeable rotor magic box, and dehumidification system

Similar Documents

Publication Publication Date Title
US7523964B2 (en) Sealing gasket for ventilation duct system
KR20170100089A (en) Gasket for air duct
US20120073239A1 (en) Flexible-Based Roof Vent for Metal Roofing
US7735891B2 (en) Corner rail extrusion
US8615943B2 (en) Adjustable roof jack
US8763325B2 (en) Adjustable roof jack
KR101529144B1 (en) Slab mounting duct connection sleeve of the building
WO2012056083A1 (en) Joining device for connecting air conditioning duct members to each other and a method for fabricating a joining device
KR101471451B1 (en) Slab mounting duct connection sleeve of the building
JP7348110B2 (en) Water stop member for segments and water stop structure for segments
KR101533344B1 (en) The air duct with banding flange and it&#39;s construction method
CA2823760C (en) Flexible register boot for heated and cooled air
CN202225873U (en) Structure for connecting air ducts of railway vehicle
EP2145136B1 (en) Method for forming a seal between air ducts and/or terminal units thereof and an air duct
CN211344343U (en) Building heating and ventilation pipeline connecting device
JP2015048574A (en) Assembly structure of corner liner plate
CN210034674U (en) Sealing structure for four corners between pipeline sections
JP2009155973A (en) Shield method segment caulking material
KR200459694Y1 (en) Spiral duct socket ring
CN210889009U (en) Colliery ventilation pipeline connection structure
KR20200120362A (en) Corner bracket for air duct and assembling method of air duct using the same
CN202368991U (en) Refrigerated container and gasket therefor
CN219530135U (en) Air pipe and fireproof soft joint thereof
JP3090951U (en) Drain port member
KR200479751Y1 (en) Sleeve having a flange connection structure of an air duct system

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E90F Notification of reason for final refusal
E601 Decision to refuse application