This disclosure relates generally to insulated doors and, more particularly, to flexible seals for insulated doors.
Horizontally sliding doors often include one or more door panels that are suspended by carriages that travel along an overhead track. To open and close the door, the carriages move the door panels in a generally horizontal direction in front of the opening of a doorway. The movement of the panels may be powered or manually operated.
Sliding doors are often used to provide access to cold-storage rooms or lockers, which are refrigerated areas in a building that are commonly used for storing perishable foods. Many refrigerated or freezer rooms are large enough for forklifts and other material handling equipment to enter and move large quantities of products in and out of the room. Access to the room is often through a power actuated insulated door that separates the room from the rest of the building. Sliding doors are often used to close off a refrigerated room because sliding panels are relatively easy to make thick with insulation to reduce the cooling load on the room. However, refrigerated rooms may have other types of doors such as swinging doors, roll-up doors, bi-fold doors, or overhead-storing doors. Regardless of the type of door applied to a refrigerated room opening, ineffectively sealing the edges around the door panels can create cooling losses and promote frost buildup in certain areas of the door.
The figures are not to scale. Instead, to clarify multiple layers and regions, the thickness of the layers may be enlarged in the drawings. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, area, or plate) is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, means that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Stating that any part is in contact with another part means that there is no intermediate part between the two parts.
Sliding doors (and/or other types of doors) used to separate cold freezer environments from warmer areas often include a seal mounted around the door frame to span a gap between the wall holding the door frame and the path along which the sliding doors translate. As a result, the door panels slide across the seal as the door panels open or close. The engagement between the door panels and the seal reduces the leakage of air between the refrigerated area on one side of the door and a warmer area on the other side. There are several challenges to achieving reliable sealing engagement between the seal and the door panels. For example, some doors are built to withstand impacts without causing significant damage to the door panels and/or the associated track and guidance system. In some examples, the effect of impacts on a door may be mitigated by providing the door with some give or positional freedom relative to a direction passing through the doorway over which the door closes. As a result, the door panels may not be in the exact same position each time they open and close such that the gap to be closed off by the seal may vary with each cycle of the door. Thus, while the seal may be in sealing engagement with the door panels at one point in time, there may be a space between the seal and the door panels at another time. Another challenge of door seals for refrigerated rooms is the formation of frost on the door, on the seal, and/or inside the seal. Such frost may have a detrimental effect upon the sealing ability of the seal.
To resolve the concern of a variably positioned door panel and/or the formation of frost, some doors include inflatable seals that are filled with heated air. The air causes the seal to inflate and span the distance between the wall and the door panel to properly engage the door panel regardless of the particular position of the door panel. Additionally, the air may be heated to reduce the likelihood of frost build up. While blowing heated air through a seal may resolve the above issues, operating such a system can be relatively expensive and the components of a blower, a heater, and ducting can take up space and require frequent maintenance.
Another solution to variably positioned door panels involves the use of a resilient foam or other material within the seal that expands to engage the surface of the door panels. Furthermore, the insulative capacity of the foam may serve to reduce the likelihood of the formation of frost. However, many resilient foam materials may lose their flexibility by setting and becoming rigid when exposed to cold temperatures (e.g., the temperature inside a refrigerated room). Thus, when such foam insulation is compressed by a door panel in a closed position for extended periods of time and subject to the cold temperatures of a refrigerated area closed off by the door panels, the foam insulation may set in its compressed form such that it will be unable to expand or move to engage the door panel if the position of the panel moves after opening and closing again.
Examples disclosed herein overcome these challenges with a seal mounted to a wall that includes a flexible sheet that is biased outwards towards the door panel via resilient insulation lining the flexible sheet. In some examples, the seal includes self-regulating heat tape within an interior cavity of the seal to heat the air within the cavity and keeps the insulation sufficiently warm to allow full flexibility despite the cold external temperature associated with a refrigerated room.
More particularly, an example seal for a door is disclosed that includes a first mounting rail and a second mounting rail spaced apart from the first mounting rail. The example seal further includes a flexible sheet extending between the first mounting rail and the second mounting rail. The flexible sheet is to be biased away from the first and second mounting rails to sealingly engage with the door when the door is in a closed position.
Another example seal for a door includes a flexible sheet having a first edge and a second edge opposite the first edge. The first edge is to be coupled to a wall adjacent to a doorway associated with the door and the second edge is to be coupled to the wall spaced apart from the first edge to define an enclosed area. The example door further includes insulation to line an inside surface of the flexible sheet facing the wall. The insulation is to bias the flexible sheet away from the wall and into a path of a door panel of the door to sealingly engage the door panel when the door panel is in a closed position.
Another example seal for a door includes a wall mount and a flexible sheet having a first edge to be secured to the wall mount and a second edge to be secured to the wall mount. The flexible sheet and the wall mount define an internal cavity. The example seal further includes a foam lining affixed to an inner surface of the flexible sheet. The foam lining is to bias the flexible sheet away from the wall mount to sealingly engage the door when the door is in a closed position. The example door also includes heat tape disposed within the internal cavity to heat the internal cavity and the foam lining.
While the illustrated example shows two horizontally translating door panels, the teachings of this disclosure may be applied to other types and/or configurations of doors. For example, the teachings of this disclosure may be applied to doors with only one panel or doors with more than two panels. Further, the teachings of this disclosure may be applied to vertically translating doors (e.g., rollup doors, overhead storage doors, etc.), pivoting doors, and/or any other type of door. Further still, the teachings of this disclosure may be applied to flexible doors (e.g., made of fabric) or rigid doors (e.g., made of fiberglass, rigid foam, metal, etc.). However, for purposes of explanation, the teachings of this disclosure will be described with reference to the example door 100 of
In the illustrated example, panels 102 and 104 are suspended from panel carriers 110 that can roll, slide, or otherwise travel along an overhead track 112. In some examples, the door panels 102, 104 of the door 100 are moved between a closed position (
In some examples, the door 100 serves to separate one area within a building from another. More particularly, in some examples, a first area 318 (
In some examples, the door panels 102, 104 are made of and/or contain thermally insulative materials to reduce heat transfer between the first and second areas 318, 320 on either side of the door 100. For example, the door panels 102, 104 may be made of a thermal insulating foam core encased in a protective cover. In other examples, the door panels 102, 104 may have a metal skin or outer structure that is filled with insulation. In other examples, the door panels 102, 104 may be formed of two flexible sheets with insulation pads disposed therebetween. Other panel structures and/or materials may additionally or alternatively be used.
In the illustrated example, the door panels 102, 104 are spaced a distance from the wall 108 to enable their movement between opened and closed positions. As a result, there may be a gap between the door panels 102, 104 and the wall 108 when the door 100 is closed. Air may pass through the gap between the areas 318, 320 on either side of the door 100. Accordingly, in the illustrated example of
As described more fully below in connection with
In some examples, the flexible sheet 144 is biased outward by resilient insulation 322 lining an inner surface of the flexible sheet 144. In some examples, the insulation 322 is made of a resilient foam that may be compressed and/or bend in response to the door panels 102, 104 coming into contact with the seal 134, but will return to its original expanded form to bias the flexible sheet 144 into the path of the door panels 102, 104 when the door panels 102, 104 are clear of the seal 134 (e.g., in the fully open position of
Inasmuch as the door 100 of the illustrated examples is intended to close off a refrigerated room, at least one side of the seal 134 may be subject to relatively cold temperatures. Such cold temperatures may deleteriously impact the resilience of the insulation 322 intended to bias the flexible sheet 144. That is, many types of resilient foam insulation materials may set or become rigid when exposed to cold temperatures for extended periods of time. In the illustrated example, to keep the refrigerated room cold, the door panels 102, 104 are in the closed position most of the time such that the resilient insulation will be in a compressed state for extended periods of times. In some examples, to reduce the likelihood of the insulation becoming rigid in this compressed state while exposed to the cool temperatures of the refrigerated area, the seal 134 includes heat tape 330 (
In some examples, vertical portions of the seal 134 (along the lateral edges 136) form miter joints with a horizontal portion of the seal 134 (along the upper edge 138) such that the seal 134 defines a tubular structure extending around the entire doorway 106 along the wall 108. In some examples, a cap 146 closes off the end or bottom 148 of the seal 134. In some such examples, the cap 146 is abutting and/or otherwise sealingly engaged with the floor to block air from passing beneath the seal 134. In some examples, the bottom 148 of the seal 134 may not be closed off with a cap 146 but directly abutting and/or otherwise sealingly engaged with the floor without the cap 146. In either case, in some examples, the bottom of the seal 134 includes an opening through which a wire may pass to electrically couple the heat tape 330 to a power source 150.
In the illustrated example, the wall mount 302 includes a first mounting rail 308 to secure the first edge 140 of the flexible sheet 144 and a second mounting rail 310 to secure the second edge 142 of the flexible sheet 144. In some examples, the first and second mounting rails 308, 310 are formed of extruded aluminum or fiberglass. In the illustrated example, the second mounting rail 310 includes an L-bracket 312 and a separate keder track 314 to facilitate mounting to the wall 108. However, in some examples, the second mounting rail 310 is made of a unitary piece. In the illustrated example, the second mounting rail 310 is fastened directly to the wall 108 (e.g., via the L-bracket 312). By contrast, the first mounting rail 308 of the illustrated example is not directly attached to the wall 108 but is attached to the second mounting rail 310 via a connecting block 316. The connecting block 316 serves to rigidly couple the first mounting rail 308 to the second mounting rail 310 while keeping the first mounting rail spaced apart from the second mounting rail 310. In some examples, the connecting block 316 is formed of a material that is less thermally conductive than the material of the first and second mounting rails 308, 310. As a result, the connecting block 316 provides a thermal break between the mounting rails 308, 310 to reduce heat transfer from one side of the seal 134 to the other side via thermal conduction through the wall mount 302.
For example, the first mounting rail 308 may be exposed to a first area 318 corresponding to a refrigerated environment (e.g., a freezer room), while the second mounting rail 310 is exposed to a second area 320 corresponding to an environment with a warmer temperature than the first area 318. Although the cold air temperature of the first area 318 may result in the first mounting rail 308 having a lower temperature, the connecting block 316 (made of a thermally insulative material) reduces heat transfer between the mounting rails 308, 310. As a result, the relatively cooler temperature of the first area 318 may be maintained more efficiently because there will be less heat loss than if the wall mount 302 was made of a unitary material that would allow heat to pass between the first and second areas 318, 320 via thermal conduction. In some examples, the first mounting rail 308 is directly fastened to the wall 108 independently of the second mounting rail 310. In some such examples, the first and second mounting rails 308 are spaced apart such that the connecting block 316 may be excluded.
As shown in the illustrated example, an inner surface of the flexible sheet 144 is lined with insulation 322. In some examples, the insulation is rubber foam, ethylene propylene diene monomer (EPDM) rubber, or other closed cell foam. In some examples, the insulation 322 is bonded to the flexible sheet 144 with an adhesive. In the illustrated example, the insulation 322 is sufficiently stiff to exert an outward biasing force on the flexible sheet 144 to cause the flexible sheet to bulge outward and away from the wall 108 and wall mount 302. More particularly, as shown in the illustrated examples, the flexible sheet 144 is biased away from the wall 108 to sealingly engage with the door panel 102 when the panel is in front of the seal 134 (e.g., when the door panel is in a closed position as shown in
In some examples, the insulation 322 is resilient to urge the flexible sheet 144 toward the expanded state after being confined to the compressed state. As a result, each time the door panel 102 opens, the insulation 322 will bias the flexible sheet 144 towards the expanded state to then contact the door panel 102 upon its closing again. In this manner, the flexible sheet 144 sealingly engages the door panel 102 each time it closes to reduce the likelihood of air leaking between the first and second areas 318, 320. In some examples, the size of the seal 134 in the expanded shape is configured to extend into the path 324 of the door panel 102 to account for potential variation in the position of the door panel 102 relative to the wall 108.
The outwardly biased flexible sheet 144 and insulation 322 defines an enclosed area or internal cavity 326 within the tubular structure of the seal 134. As shown in the illustrated examples, the insulation 322 extends substantially between the first edge 140 of the flexible sheet 144 and the second edge 142 of the flexible sheet 144. In this manner, the insulation 322 serves to insulate the air within the cavity 326 from the surrounding areas 318, 320. In some examples, the seal 134 includes an insulation block 328 positioned against the wall mount 302 (including the first mounting rail 308, the second mounting rail 310, and the connecting block 316) to separate the air within the cavity 326 from the wall 108 and the components of the wall mount 302, which may be cold due to exposure to the cold temperatures of the first area 318. In some examples, the insulation block 328 is formed of the same material as the insulation 322 lining the flexible sheet 144. In some examples the insulation block 328 is formed of the same material as the connecting block 316. In some examples, the connecting block 316 is integrally formed with the insulation block 328. In some examples, the insulation 322 is in contact with the insulation block 328 such that the air within the cavity 326 is enclosed by insulative material.
The doors to a cold-storage or other refrigerated room are typically kept closed most of the time to maintain the desired temperature. As a result, in such examples, the seal 134 is likely to be in the compressed state (pressed against the surface of the closed door panel 102) most of the time. Although the insulation 322 may be resilient under normal temperature environments (e.g., room temperature), when exposed to the much cooler temperatures of a refrigerated room, there is the possibility of the insulation setting and becoming stiff That is, at low temperatures, the insulation 322 may harden into position in the compressed state such that it no longer expands to extend into the path 324 of the door panel 102 when the door panel opens. In such a situation there is the possibility that when the door panel 102 closes again, a proper seal between the flexible sheet 144 of the seal 134 and the door panel 102 may not be achieved. Accordingly, in some examples, the seal 134 includes heat tape 330 disposed along the interior cavity 326 (e.g., on the insulation block 328) to heat the air enclosed therein and the insulation 322 such that the insulation 322 maintains resilience even when exposed to the relatively cold temperatures of a refrigerated area. Furthermore, in some examples, the heat produced by the heat tape 330 reduces the likelihood of frost forming on the seal 134 (on either the inside or on the outside). In some examples, the heat tape 330 is self-regulating heat tape to increase heat output when the temperature decreases and to decrease heat output when the temperature increases. The particular capacity of the heat tape 330 depends on the size of the seal 134 and the environment in which the seal 134 is implemented. In some examples, the heat tape 330 uses 8 watts per foot.
For purposes of explanation, the portion of the door panels 1102, 1104 where the protrusion 1106 is located (along outer lateral and top edges 1108, 1110) is referred to herein as the outer edge 1112 of the door panels 1102, 1104. The remaining portion of the door panels 1102, 1104 (excluding the outer edge 1112) is referred to herein as the main body 1114 of the door panels. As shown in the illustrated examples of
As shown in the illustrated example of
The particular size and/or shape of the protrusion 1106 may be suitably adapted to the configuration of the seal 134 and/or the position of the door panels 1102, 1104 relative to the wall 108. In some examples, the protrusion 1106 is configured with a width approximately the same as or slightly larger than (e.g., twice the size of) a width of the seal 134 to ensure proper sealing engagement. Further, in some examples, the protrusion 1106 is configured such that the difference in the distance that the seal 134 extends from the wall 108 between the compressed state (
From the foregoing, it will appreciate that the above disclosed methods, apparatus and articles of manufacture enable the effective sealing of doors to a refrigerated room by lining a flexible sheet with resilient insulation to bias the flexible sheet into engagement with door panels in a closed position. Example seals disclosed herein include heat tape to heat the insulation so that it maintains its resilience or flexibility even when compressed and subject to the cold temperature environments of a refrigerated room for extended periods of times. Furthermore, example seals disclosed herein include a wall mount made of spaced apart mounting rails coupled via a thermally insulative connecting block to reduce heat conduction from a warm side of the seal to a cold side of the seal, thereby reducing the cooling load on the refrigerated room.
Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the claims of this patent.
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