AU704045B2

AU704045B2 - Heat tracking-resistant connecting structure for air handling unit

Info

Publication number: AU704045B2
Application number: AU37607/97A
Authority: AU
Inventors: Tom Chang
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1997-03-27
Filing date: 1997-09-17
Publication date: 1999-04-15
Anticipated expiration: 2017-09-17
Also published as: TW326903U; AU3760797A

Description

Heat Tracking-Resistant Connecting Structure for Air Handling Unit FIELD OF INVENTION The present invention relates to a heat tracking-resistant connecting structure for use in a casing, particularly in the casing of an air handling unit that has a sturdy, airtight, and fireproof construction, and that resists heat tracking and condensation while eliminating metal to metal contact between its inner and outer skins. Furthermore, the heat tracking-resistant connecting structure enhances rigidity of the casing, prevents power loss, and reduces possibility of damaging the air handling unit.

o o *ooo 10 BACKGROUND OF INVENTION The conventional casing structure for air handling units comprises a frame constructed of metal columns and a plurality of insulated panels being bolted to the metal columns to form an enclosure. However, in such a conventional casing structure, metal contact is always established between the inner and outer 15 skins after assembly (as shown Fig. 1A) such that indirect thermal conductivity occurs between interior cooler, dryer air and the exterior, warmer, damper air of the casing, whereby temperature of interior air is elevated by heat absorbed from exterior air as a result of metal contact between the inner and outer skins of the casing. Moisture in exterior air is found to condense on the outer skin thereby losing the power intended for reducing temperature of interior air.

Moisture condensed on the outer skin further corrodes the casing and causes damages to the unit and contaminates the environment. Moreover, direct contact between rigid, metal materials established by the conventional connecting structure results in substandard airtight characteristic, which eventually evolves into a hidden communication path between interior and exterior air of the casing.

Furthermore, in the event of sever impact, deformation is commonly observed at the bolted sections of the conventional connecting structure because U:APTS\CKC\ENG\47154E.DOC rigidity of the conventional casing is primarily relied on the bolts which secure panels to the metal columns.

Other conventional structure also includes insulation material exposed to interior air of the casing (as shown in Fig. 1B). The flammable insulation material in such a structure is found to be a hidden fire hazard due to its vulnerability to fire.

It would therefore be desirable to provide a heat tracking-resistant connecting structure for an air handling unit that has a sturdy, airtight, and fireproof construction, and that resists heat tracking and condensation while eliminating metal to metal contact between its inner and outer skins. It would also be desirable to provide a heat tracking-resistant connecting structure for an air handling unit having superior rigidity to prevent deformation of the casing in the event of severe impact or improper usage. Furthermore it would be useful to provide a heat tracking-resistant connection structure for an air handling unit .that meets the fireproof standards stipulated in BS-476.

Summary of Invention According to an aspect of the present invention there is provided a heat tracking-resistant connecting structure for an air handling unit, including: a first panel including an inner skin and an outer skin spaced from each other in parallel, and an insulation gasket; wherein said outer skin has an edge being folded towards said inner skin to form an outer fold; said inner skin has a corresponding edge being folded towards said outer skin at a location spaced from said outer fold to form a first inner fold, and then towards said outer fold to form a second inner fold, said first inner fold being distant from said outer skin by an adequate gap, and said second inner fold having an end edge being distant from said outer fold by an adequate gap; said insulation gasket is Ssecurely wrapped about opposing surfaces of the free end of said second inner V1-2- VT C \WINWORD\VIOLET\PHIL\NOD ELE7 E 37607-97 DOC fold; and said inner skin and said outer skin is injected with foam insulation therebetween; a second panel including an inner skin and an outer skin spaced from each other in parallel, and an insulation gasket; wherein said outer skin has an edge being folded towards said inner skin to form an outer fold; said inner skin has a corresponding edge being folded towards said outer skin at a location spaced from said outer fold to form an inner fold, said inner fold having an end edge being distant from said outer skin by an adequate gap, and said outer fold having an end edge being distant from said inner skin by an adequate gap; said insulation gasket is secured between said inner fold and said outer fold; said inner skin and said outer skin is injected with foam insulation therebetween; and said second panel is assembled to said first panel in an angled relation to define ooo* two neighboring panels of said air handling unit; and "an airtight joint including an elongated reinforcing member being folded *along its longitudinal axis and affixed to said neighboring first and second panels.

The above and further features and advantages of this invention will be readily realized by those skilled in the art from the following detailed description of the preferred embodiments of the invention with reference to accompanying *.*drawings.

Brief Descriptions of Drawings Fig. 1A is a cross-sectional, assembled view of two neighboring, perpendicular panels of the casing of a conventional air handling unit; -2a- VT C:\WINWORD\VIOLEP\PHIL\NODELETE\3 7 6 07 97 DOC Fig. 1B is a cross-sectional, assembled view of two neighboring, perpendicular panels of the casing of a further conventional air handling unit; Fig. 2 is a perspective view of a heat tracking-resistant casing for an air handling unit according to this invention; Fig. 3 is a cross-sectional, exploded view taken along lines 4-4 of Fig. 2; Fig. 4 is a cross-sectional, assembled view taken along lines 4-4 of Fig. 2; Fig. 5 is an exploded view of the connecting structure of a corner of the casing illustrated in Fig. 2; and Fig. 6 is a perspective, assembled view of Fig. 10 Detailed Descriptions of Preferred Embodiments Referring to Fig. 2, where a perspective view of a heat tracking-resistant casing 1 for an air handling unit according to this invention is illustrated. As shown in the figure, the casing 1 is substantially in a rectangular configuration having eight comers 100. Figs. 3 and 4 respectively illustrate a cross- 15 sectionally exploded and assembled views taken along lines 4-4 of Fig. 2, where a connecting structure 10 of two neighboring, perpendicular panels of the casing 1 is illustrated.

c..

The connecting structure 10 comprises a first panel 20, a second panel and an airtight joint 40. The first panel 20 includes an inner skin 22 and an outer skin 24 spaced from each other in parallel, and an insulation gasket 26.

The outer skin 24 has an edge being folded towards the inner skin 22 to form an outer fold 242. The inner skin 22 has a corresponding edge being folded towards the outer skin 24 at a location spaced from the outer fold 242, and then towards the outer fold 242 to form a first inner fold 222 and a second inner fold 224. The first inner fold 222 is distant from the outer skin 24 by an adequate gap. The second inner fold 224 is distant from the outer skin 24, and has an end edge being distant from the outer fold 242 by an adequate gap of distance d, whereby a receiving groove 25 of width L is jointly formed by the first inner U:\PTS\CKC\ENG\47154E.DOC -3 fold 222, the second inner fold 224, and the outer fold 242. The insulation gasket 26 has a thickness substantially equal to or slightly greater than the distance d and is securely wrapped about opposing surfaces of the free end of the second inner fold 224 to preclude the end edge of the second inner fold 224 from contacting the outer fold 242, and to insulate the inner sin 22 from the outer skin 24. The panel 20 jointly formed by the inner skin 22, the outer skin 24, and the first inner fold 222 has a thickness wherein the panel 20 is injected with foam insulation 52 to insulate the inner 22 from the outer skin 24.

The second panel 30 includes an inner skin 32 and an outer skin 34 spaced from each other in parallel, and an insulation gasket 36. The outer skin 34 has ~an edge being folded towards the inner skin 32 to form an outer fold 342, which is distant from the inner skin 32. The inner skin 32 has a corresponding edge being folded towards the outer skin 34 at a location spaced from the outer fold S342. The inner fold 322 has an end edge being distant from the outer skin 34 15 by an adequate gap of distance The insulation gasket 26 has a thickness substantially equal to or slightly greater than distance d' and is at least secured between the inner fold 322 and the outer fold 342, preferably securely wrapped about opposing surfaces of the free end of the inner fold 322 to preclude the end edge of the inner fold 322 from contacting the outer fold 342, and to insulate the inner skin 32 from and the outer skin 34, whereby an insertion edge 35 for inserting into the receiving groove 25, is jointly formed by the inner skin 32, the outer skin 34, the inner fold 322, and the outer fold 342. The panel 30 jointly formed by the inner skin 32, 34 and the inner fold 322 has a thickness

L",

wherein the panel 30 is injected with foam insulation 53 to insulate the inner skin 32 from the outer skin 34. The panel thickness L"is substantially equal to or slightly smaller than the width L of the receiving groove 25 of the second panel 20. Preferably, the panel thickness L' of the first panel 20 is substantially equal to the panel thickness L" of the second panel 30 and the distance d is substantially equal to the distance d'.

The airtight joint 40 includes an elongated reinforcing member 42 folded along its longitudinal axis. Preferably, an insulation gasket 46 is securely wrapped about the outward, perpendicular faces 48 of the reinforcing member U:\PTS\CKC\ENG\47154E.DOC

M

42, wherein the outward, perpendicular faces 48 are affixed to the perpendicular faces of the two neighboring, perpendicular first panel 20 and second panel by means of a plurality of bolts 44, whereby the insulation gasket 46 is located between the first, second panels 20, 30 and the reinforcing member 42 to enhance rigidity of the two perpendicular panels 20, 30 and to insulate the neighboring, perpendicular faces of the first, second panels 20, 30 from exterior air. Fig. 4 is a cross-sectional view illustrating the two neighboring, perpendicular panels 20, 30 after assembly.

Fig. 5 is a perspective, exploded view of the connecting structure of Figs. 3 and 4 being implemented to a comer 100 of the casing 1. Fig. 6 is a perspective, assembled view of the comer 100 of the casing 1. As illustrated in Fig. 5, the comer 100 of the casing 1 is constructed of a bottom panel 11, a right side panel 12 perpendicular to the bottom panel 11, and a rear panel 13 perpendicular to the right side panel 12 and the bottom panel 11. The bottom 15 panel 11 has two perpendicular, outer edges 111, 112 being each formed with a ~receiving groove 25 as that illustrated in Fig. 4. The right side panel 12 has two perpendicular, outer edges 121, 122 being each formed with an insertion edge 35 as that illustrated in Fig. 4. The horizontal edge 122 of the right side panel 12 is adapted to be inserted into the receiving groove 25 formed along the outer edge 111 of the bottom panel 11. The rear panel 13 has a vertical edge 131 being formed with a receiving groove 25, in which the vertical edge 121 of the right side panel 12 is inserted, and a vertical edge 132 being formed with an insertion edge 35 adapted to be inserted into the receiving groove 25 formed along the other outer edge 112 of the bottom panel 11. After assembly, the three neighboring, perpendicular panels 11, 12, 13 are then secured to each other by means of airtight joints 40 and bolts 44 as shown in Fig. 6.

To ensure a tight seal among the three airtight joints at the corner of the casing 1, their joining edges 49 are machined in a manner that complements each other. A common method is to machine the joining edges 49 at an angle of 450 such that the joining edges 49 jointly form a joining comer as that shown in Fig. 6. A casing for an air handling unit after assembly is as illustrated in Fig. 2.

U:\PTS\CKC\ENG\47154E.DOC The inner, outer skins and the reinforcing members described previously are made of any suitable rigid metals, such as galvanized steel. The insulation injected between the inner and outer skins includes any suitable foam insulation, such as polyurethane. The insulation gasket wrapped about the free ends of the inner folds or about the outward faces of the reinforcing members are made of any suitable insulation material having established configurations, such as polyethylene.

As shown in Fig. 4, the insulation gaskets 26, 36 and the foam insulation 52, 53 of the connecting structure 10 preclude the inner and outer skins from contacting each other after assembly of two neighboring, perpendicular panels and thus eliminate indirect thermal conductivity between the inner and outer skins of the casing. Therefore, this invention eliminates temperature elevation due to heat absorbed from exterior air as a result of metal contact between the inner and outer skins of the casing, prevents moisture in exterior air from S. 15 condensing on the outer skin of the casing, and precluding power loss, as those of the conventional structures. This invention ultimately eliminates corrosion and damages caused by moisture condensed on the outer skin.

Moreover, direct metal to metal contact between neighboring, perpendiculai panels of the conventional structures is substituted by metal to flexible insulation contact between the receiving grooves 25 and the insertion e" edge 35, and between the reinforcing members 42 and the inner skins 22, 32.

*eee. During assembly, two neighboring, perpendicular panels are tightly pressed against each other prior to bolting the airtight joints 40 to the panels. Such a connecting structure provides an airtight characteristic superior to the conventional structures and further eliminates a hidden communication path between interior and exterior air of the casing. As shown in Fig. 6, the connecting structure for the air handlingunit of this invention is constructed of integrally formed panels instead of inner or outer columns thereby providing a higher resistance to deformation in the event of sever impact.

Finally, the casing according to this invention precludes insulation material from exposing to interior air of the casing because the foam insulation is U:\PTS\CKC\ENG\47154E.DOC completely surrounded with the inner and outer skins of the panels thereby providing a fireproof construction having a higher resistance to fire.

Aforementioned explanation is directed to the descriptions of a preferred embodiment according to this invention. Various changes and implementations, such as forming the inner folds by bending the outer skins, forming the outer folds by bending the inner skins, or modifying the relative arrangement of the receiving grooves and the insertion edges at a specific corer of the casing, can all be made by those skilled in the art without departing from the technical concept of this invention. Since this invention is not limited to the specific details described in connection with the preferred embodiment except those that may be within the scope of the appended claims, changes to certain features of the preferred embodiment without altering the overall basic function of the invention are contemplated.

o• *b 0 U:\PTS\CKC\ENG\47154E.DOC The claims defining the invention are as follows: A heat tracking-resistant connecting structure for an air handling unit, including: a first panel including an inner skin and an outer skin spaced from each other in parallel, and an insulation gasket; wherein said outer skin has an edge being folded towards said inner skin to form an outer fold; said inner skin has a corresponding edge being folded towards said outer skin at a location spaced from said outer fold to form a first inner fold, and then towards said outer fold to form a second inner fold, said first inner fold being distant from said outer skin by an adequate gap, and said second inner fold having an end edge being distant from said outer fold by an adequate gap; said insulation gasket is securely wrapped about opposing surfaces of the free end of said second inner fold; and said inner skin and said outer skin is injected with foam insulation therebetween; S 15 a second panel including an inner skin and an outer skin spaced from each other in parallel, and an insulation gasket; wherein said outer skin has an edge being folded towards said inner skin to form an outer fold; said inner skin has a corresponding edge being folded towards said outer skin at a location spaced from said outer fold to forman inner fold, said inner fold having an end edge being distant from said outer skin by an adequate gap, and said outer fold having an end edge being distant from said inner skin by an adequate gap; said insulation gasket is secured between said inner fold and said outer fold; said inner skin and said outer skin is injected with foam insulation therebetween; and said second panel is assembled to said first panel in an angled relation to define two neighboring panels of said air handling unit; and an airtight joint including an elongated reinforcing member being folded along its longitudinal axis and affixed to said neighboring first and second panels.

Claims

2. The heat tracking-resistant connecting structure for an air handling unit according to claim 1, wherein said first inner fold, said second inner fold, and said outer fold of said first panel jointly form a receiving groove, and said outer skin, said inner fold, and said inner skin of said second panel jointly form an insertion edge adapted to be inserted into said receiving groove such that said first and second panels jointly form two neighboring, perpendicular panels of said casing.
3. The heat tracking-resistant connecting structure for an air handling unit according to claim 2, wherein said reinforcing member has two neighboring, perpendicular, outward faces being affixed to said inner skins of said neighboring, perpendicular first and second panels.
4. The heat tracking-resistant connecting structure for an air handling unit according to claim 1, wherein said insulation gasket of said second panel is wrapped about opposing surfaces of the free end of said inner fold of 15 said second panel. The heat tracking-resistant connecting structure for an air handling unit S according to claim 3, wherein said airtight joint further includes an insulatiQn gasket wrapped about said outward faces of said reinforcing member. S 20 6. The heat tracking-resistant connecting structure for an air handling unit according to claim 5, wherein said airtight joint is affixed to said inner skins of said neighboring, perpendicular first and second panels by means of a plurality of bolts.
7. The heat tracking-resistant connecting structure for an air handling unit according to claim 2, wherein said receiving groove is of width L, said first panel has a thickness and said second panel has a thickness L" being substantially equal to said thickness L'.
8. The heat tracking-resistant connecting structure for an air handling unit according to claim 7, wherein said thickness L" is substantially equal to said width L.
9. The heat tracking-resistant connecting structure for an air handling unit according to claim 1, wherein said second inner fold of said first panel is distant from said outer skin of said first panel by a distance d, and said end edge of said second inner fold of said first panel is distant from said outer fold of said first panel by a distance d; and said end edge of said inner fold of said second panel is distant from said outer skin of said second panel by a distance and said insulation gasket of said first panel has a thickness being substantially equal to said distance d, and said insulation gasket of said second panel has a thickness being substantially equal to said distance d'. The heat tracking-resistant connecting structure for an air handling unit according to claim 9, wherein said distance d is substantially equal to said distance d'.
11. The heat tracking-resistant connecting structure for an air handling unit according to claim 1, wherein said inner skins, said outer skins, and said reinforcing member are made of galvanized steel. 20 12. The heat tracking-resistant connecting structure for an air handling unit according to claim 1, wherein said foam insulation is made of *polyurethane.
13. The heat tracking-resistant connecting structure for an air handling unit according to claim 1, wherein said insulation gaskets are made of polyethylene.
14. A heat tracking-resistant connecting structure for an air handling unit, incrbding: a first panel including an inner skin and an outer skin spaced from each other in parallel, and an insulation gasket; wherein said outer skin has an 10 edge being folded towards said inner skin to form an outer fold; said inner skin has a corresponding edge being folded towards said outer skin at a location spaced from said outer fold to form a first inner fold, and then towards said outer fold to form a second inner fold, said first inner fold being distant from said outer skin by an adequate gap of distance d, and said second inner fold having an end edge being distant from said outer fold by an adequate gap of distance d, wherein said first inner fold, said second inner fold, and said outer fold jointly form a receiving groove of width L; said insulation gasket has a thickness being substantially equal to said distance d and is securely wrapped about opposing surfaces of the free end of said second inner fold; and said first panel formed by said inner skin and said outer skin form has a thickness L' and is injected with foam insulation therebetween; *4 a second panel including an inner skin and an outer skin spaced from each other in parallel, and an insulation gasket; wherein said outer skin has an •.edge being folded towards said inner skin to form an outer fold; said inner skin has a corresponding edge being folded towards said outer skin at a location spaced from said outer fold to form an inner fold, said inner fold having an end edge being distant from said outer skin by an adequate gap 20 of distance d' and said outer fold having an end edge being distant from said inner skin by an adequate gap of distance said insulation gasket has a thickness being substantially equal to said distance d' and is secured between said inner fold and said outer fold, wherein said outer skin, said inner fold, and said inner skin jointlyforman insertion edge adapted to be inserted into said receiving groove such that said first and second panels jointly form two neighboring, perpendicular panels of said casing; and said second panel formed by said inner skin and said outer skin has a thickness L" being substantially equal to or slightly less than said width L and is injected with foam insulation therebetween; and an airtight joint including an elongated reinforcing member being folded along its longitudinal axis to form two neighboring, perpendicular, C F TS\CKC\ENG\47154E DOC -11- outward faces that are affixed to said inner skins of said neighboring, perpendicular first and second panels. The heat tracking-resistant connecting structure for an air handling unit according to claim 14, wherein said insulation gasket of said second panel is wrapped about opposing surfaces of the free end of said inner fold of said second panel.
16. The heat tracking-resistant connecting structure for an air handling unit according to claim 14, wherein said airtight joint further includes an insulation gasket wrapped about said outward faces of said reinforcing member. S17. The heat tracking-resistant connecting structure for an air handling unit ~according to claim 16, wherein said airtight joint is affixed to said inner skins of said neighboring, perpendicular first and second panels by means of a plurality of bolts. S 15 18. The heat tracking-resistant connecting structure for an air handling unrit according to claim 14, wherein said thickness L" is substantially equal to said width L.
19. The heat tracking-resistant connecting structure for an air handling unimt according to claim 14, wherein said distance d is substantially equal to said distance d'. The heat tracking-resistant connecting structure for an air handling unit according to claim 14, wherein said inner skins, said outer skins, and said reinforcing member are made of galvanized steel.
21. The heat tracking-resistant connecting structure for an air handling unit according to claim 14, wherein said foam insulation is made of polyurethane.
22. The heat tracking-resistant connecting structure for an air handling unit according to claim 14, wherein said insulation gaskets are made of polyethylene.
23. A heat tracking-resistant connecting structure for an air handling unit substantially as herein described with reference to the accompanying drawing Figs. 2 to 6. DATED: 23 October 1998 PHILLIPS ORMONDE FITZPATRICK Attorneys for: CARRIER CORPORATION 0 o o -13- MCR C \WINW0RD\MARY\NODELETE\37607 DC( Heat Tracking-Resistant Connecting Structure for Air Handling Unit ABSTRACT The present invention relates to a heat tracking-resistant connecting structure for use in the casing for an air handling unit, comprising a first panel and a second panel. The first panel includes an inner skin and an outer skin isolated by foam insulation, wherein the outer skin has an edge being folded towards the inner skin to form an outer fold, and the inner skin has a corresponding edge being folded towards the outer skin at a location spaced from the outer fold, and then towards the outer fold to form an inner fold such S* 10 that a receiving groove is jointly formed by the inner skin, and the inner, outer folds. The inner fold is provided with a insulation gasket to insulate the inner fold from the outer fold. The second panel includes an inner and an outer skins isolated by foam insulation, wherein the inner and outer skins each have a corresponding edge being folded towards each other to, respectively, form an 15 inner and an outer folds which jointly form an insertion edge. The insertion edge is inserted into the receiving groove of the first panel to build two neighboring, perpendicular panels of the casing. 4 p 8 •eo oooo q U:\PTS\CKC\ENG\47154E.DOC 14-