Patent Description:
A through-air apparatus generally includes a rigid air-permeable web-carrying structure, known as a through-air roll. A web is placed on the through-air roll, and as the web-carrying structure rotates, a fan may blow air through the wall of the through-air roll to treat the web. The through-air roll typically has a plurality of openings to permit the air to pass through the roll.

Systems and methods related to through-air drying are commonly referred to through the use of the "TAD" acronym. Systems and methods related to through-air bonding are commonly referred to through the use of the "TAB" acronym.

<CIT>) discloses a heat treatment apparatus, for example, drying polymerizing, and curing of material impregnated with synthetic resins and for heat-setting materials of all kinds, preferably natural and synthetic fibrous materials.

In the invention, a high performance through-air apparatus is provided. The though-air apparatus includes a through-air roll configured for rotational movement about a first axis, and a high flow circuitous air path inside of the apparatus that includes a path extending through a supply conduit, through the through-air roll, and also through an exhaust conduit. The through-air apparatus also includes a plurality of turning vanes positioned within the high flow circuitous path positioned to guide the flow of air through the apparatus. The through-air apparatus has a length, a width, a height, which together define a volume having a compact configuration. The high flow circuitous air path inside of the apparatus has a length of at least <NUM>, where the ratio of the volume of the through-air apparatus to the length of the high flow circuitous air path is less than <NUM><NUM>.

The present disclosure is directed to a through-air apparatus configured to manufacture various products, such as paper, tissue, and/or nonwoven webs. One of ordinary skill in the art would recognize that the through-air apparatus may be configured as a through-air dryer (TAD) and/or a through-air bonder (TAB), depending on the context in which the apparatus is used. One of ordinary skill in the art will also recognize that the through-air apparatus may be used to make various web products that are rolled in their finished end product form. It should also be recognized that the product may not be rolled and/or may be cut into a finished end product. Furthermore, one of ordinary skill in the art will also recognize that the through-air apparatus may be configured to make various products, including, but not limited to various films, fabric, or other web type material, and the apparatus may be used for various processes that may include mass transfer, heat transfer, material displacement, web handling, and quality monitoring, including, but not limited to drying, thermal bonding, sheet transfer, water extraction, web tensioning, and porosity measurement.

As set forth in more detail below, the through-air apparatus includes a rigid air-permeable web-carrying structure, known as a through-air roll, configured to rotate relative to another portion of the apparatus. A web is placed on the through-air roll, and as the web moves, a fan may blow air through the wall of the through-air roll to treat the web. The through-air roll typically has a plurality of openings to permit the air to pass through the structure.

As an overview, a web (i.e. product) is typically in a sheet-form and it is partially wrapped around the through-air roll of the through-air apparatus. The web is wrapped about a portion of the roll ranging from, for example, <NUM>° to <NUM>°, and typically between <NUM>° - <NUM>° around the roll. A fan/blower is used to circulate the air across the product, and the through-air roll is typically positioned within a hood to optimize the air flow characteristics. As the product travels with the rotating through-air roll, through the active zone of the apparatus, the fan/blower circulates air through the wall of the through-air roll to treat the product. A heater may be provided so that heated air circulates through the through-air roll.

One embodiment of the through-air apparatus <NUM> is illustrated in <FIG>. As shown, the through-air apparatus <NUM> includes a though-air roll <NUM> that is configured to carry a web <NUM> and rotate about a first axis <NUM>. As set forth in more detail below, aspects of the present disclosure are directed to a through-air apparatus <NUM> having a high flow circuitous flow path inside of the apparatus. The system includes a fan <NUM> that directs system air (also known as process air) along the flow path and into the through-air roll <NUM>. As set forth in more detail below, this circuitous flow path enables the overall volume of the apparatus to be smaller than a conventional through-air apparatus.

A through-air apparatus <NUM> is often a very large machine. For example, the through-air roll <NUM> may have a length between <NUM> meters - <NUM> meters (<NUM> foot - <NUM> feet), and a diameter between <NUM> meters - <NUM> meters (<NUM> foot - <NUM> feet).

The inventors recognized that a conventional through-air apparatus generally falls into two categories: (<NUM>) a compact through-air apparatus which may have difficulty meeting product quality needs and with lower production throughput; or (<NUM>) a high performance, high throughput through-air apparatus that requires a large machine air system which may be difficult to fit in some machine spaces. In addition, the cost of these large and cumbersome high performance through-air apparatus systems may be high. Furthermore, the large high performance machines also typically have a long lead time from sale to delivery, including large shipment sizes from the point of manufacture, and having a large amount of void volume during shipping due to the way a conventional duct is constructed. Machine installation may be complex requiring significant calendar time, skills and building space.

Recognizing some of the problems associated with the conventional designs, aspects of the present disclosure are directed to a compact through-air apparatus which includes some of the features of a large high-performance through-air apparatus with the benefits of lower capital costs to the consumer, shorter lead times, and a smaller overall size which means that less building space is required.

End user product properties drive the need for tight air flow and temperature uniformity for a through-air apparatus. For example, current technology requires the machine builder of a through-air bonder to provide a large external air system to meet the high performance requirements of a +/- <NUM> for air temperature and <NUM>% peak to peak for air pressure supplied to the product to be bonded. As set forth in more detail below, in one embodiment, the through-air apparatus <NUM> uses a unique combination of different technologies to meet these high performance requirements while maintaining a small machine footprint and/or a small machine volume.

Also, as set forth in more detail below, aspects of the present disclosure are directed to a through-air apparatus which utilizes a panelized construction. For example, as shown in <FIG>, in one embodiment, the through-air apparatus <NUM> is made of a plurality of panels <NUM> which are assembled together to form the through-air apparatus <NUM>. The inventors recognized that this modular panelized design may allow for ease of manufacturing, provide compact shipping, and/or may also improve accessibility and maintenance. Further details regarding these panels <NUM> are disclosed in <FIG> and described in more detail below.

Turning now to <FIG>, the inside of the apparatus <NUM> will now be described. <FIG> illustrate different portions of the through-air apparatus <NUM> according to one embodiment. The through-air apparatus <NUM> includes a through-air roll <NUM>, a supply conduit <NUM>, and an exhaust conduit <NUM>. <FIG> illustrates a through-air roll <NUM> and an exhaust conduit <NUM> (with the supply conduit <NUM> omitted), and <FIG> illustrates a through-air roll <NUM> and a supply conduit <NUM> (with the exhaust conduit <NUM> omitted). As an overview, air travels through the supply conduit <NUM>, through the through-air roll <NUM>, and then through the exhaust conduit <NUM>. In one embodiment, this is a recirculating air path. In one embodiment, there is a make-up air damper so that some new air enters the air path and a dump to atmosphere so air exits the air path. This defines a high flow circuitous air path which extends through the supply conduit <NUM>, the through-air roll <NUM>, and the exhaust conduit <NUM>. As described in more detail below, this circuitous flow path enables the overall volume of the apparatus to be smaller than a conventional through-air apparatus. The inventors recognized that having a winding and/or meandering air flow path enables one to achieve a particular desired overall air flow path length within a smaller volume. Further details regarding embodiments having an extraction conduit configured to dump to atmosphere is described below and shown in <FIG> and <FIG>.

As shown, in one embodiment, the supply conduit <NUM> is bifurcated into a first supply conduit <NUM> positioned on a right side of the apparatus <NUM> and a second supply conduit <NUM> positioned on a left side of the apparatus <NUM>, and the exhaust conduit <NUM> is configured to be interposed between the first supply conduit <NUM> and the second supply conduit <NUM>. The inventors recognized that sharing common walls between the supply conduit <NUM> and the exhaust conduit <NUM> is one way to achieve a more compact design. In other words, a first side of a common wall may act as a portion of the supply conduit <NUM>, whereas a second opposite side of the common wall may act as a portion of the exhaust conduit <NUM>. Further details within both the supply conduit <NUM> and the exhaust conduit are described below.

The inventors recognized that this design enables the through-air apparatus <NUM> to have high performance air flow characteristics in a compact space. As shown in <FIG>, the through-air apparatus <NUM> has a length L, a width W, and a height H, which together define a volume. As described further below, in one embodiment, the high flow circuitous air path inside of the apparatus has a length, and the ratio of the volume of the through-air apparatus <NUM> to the length of the high flow circuitous air path is less than <NUM><NUM>. As discussed in more detail below, the air path length is calculated as the entire distance a molecule of air travels as it circulates through the through-air apparatus along the centerline of the conduits (i.e. ducting network defined by the through-air roll <NUM>, the exhaust conduit <NUM> and the supply conduit <NUM>) and completes one full circuit, thus returning to its point of origin. As shown in <FIG>, in one embodiment, the Length L of the apparatus <NUM> is defined as the dimension substantially parallel with the first axis <NUM> (i.e. axis of rotation of the through-air roll <NUM>). In other words, the first axis <NUM> is substantially parallel to the length L of the through-air apparatus <NUM>.

Turning now to <FIG>, one embodiment of the high flow circuitous air path inside of the through-air apparatus is shown in more detail. <FIG> illustrates the circuitous air path through the exhaust conduit <NUM> (also known as the suction side of the main fans <NUM>). <FIG> illustrates the circuitous air path through the supply conduit <NUM> (also known as the pressure side of the main fans <NUM>). <FIG> illustrates the hood formed by the supply conduit <NUM> which wraps around the through-air roll <NUM>. As shown in <FIG> and <FIG>, air passes through the inside of the through-air roll <NUM> as shown by arrows A. The air travels along the first axis <NUM> of the through-air roll <NUM>, out an exhaust end of the roll <NUM> and into the exhaust conduit <NUM> as shown by arrows B and C.

As shown in <FIG>, the exhaust conduit <NUM> may include a plurality of turning vanes 20a, 20b which are positioned to guide the flow of air through the apparatus <NUM>. One of ordinary skill in the art will recognize that turning vanes 20a, 20b assist the airflow in making a smoother and more gradual change in direction in the exhaust conduit <NUM>, resulting in reduced turbulence. Downstream of the turning vanes 20a, 20b, the exhaust conduit <NUM> includes a flow straightener <NUM>, which is used to guide the flow of air by straightening the air flow in a conduit. One of ordinary skill in the art will recognize that a flow straightener is typically a passage of ducts, positioned along the axis of air stream to minimize the lateral velocity components caused by swirling motion in the air flow. As shown, a heating source <NUM> may also be provided within the exhaust conduit <NUM> to heat up the air. The air may travel by the heating source <NUM> as shown by arrow D. Thereafter, the air passes through a plurality of mixing plates <NUM> positioned adjacent the heating source <NUM>. It should be recognized that the plurality of mixing plates <NUM> are configured to mix the air to more evenly distribute the heat to achieve more uniform temperature profile. It is contemplated that the heating source <NUM> may be an electric heater, a heat exchanger, a direct fixed burner, an indirect fixed burner, or any other thermal energy source.

After passing through the heating source <NUM> and mixing plates <NUM>, the air flow exits the exhaust conduit <NUM> and enters the supply conduit <NUM>. As shown in <FIG>, the air is drawn through one or more fans <NUM> positioned at the entrance of the first supply conduit <NUM> and the second supply conduit <NUM>. As shown in the figures, regardless of whether the air passes through the first or the second supply conduit <NUM>, <NUM>, its overall air flow path remains the same as shown in <FIG>. The air initially passes up through the supply conduit <NUM> as shown by arrow E and passes through a first static mixer 70a. One of ordinary skill in the art will recognize that a static mixer is a device for the continuous mixing of fluid materials, without moving components. As shown in <FIG>, the supply conduit <NUM> may include a plurality of turning vanes 20C, followed by one or more additional static mixers 70b, 70c, as shown by arrow F. Thereafter the air flow goes through an additional set of turning vanes 20d, and extends down to the outer diameter of the through-air roll <NUM> as shown by arrows G. As discussed above, the air flow path then crosses through the through-air roll as shown by arrows A shown in <FIG> and <FIG>. This recirculating air path is repeated.

One of ordinary skill in the art will appreciate that the exact location of the components within the exhaust conduit <NUM> and the supply conduit <NUM> may vary according to different embodiments. The various air mixing devices (turning vanes 20A, 20B, 20C, 20D, flow straightener <NUM>, mixing plates <NUM>, and static mixers 70A, 70B, 70C) all assist in elevating the performance of the through-air apparatus <NUM> to provide flow and temperature uniformity. In one embodiment, mixing is being initiated and allowed throughout the circuitous air path. There may be forced mixing upstream of the fans <NUM> and also static mixers downstream of the fans <NUM>. There may also be localized directional mixing between the turning vanes 20A, 20B, 20C, 20D. As shown in <FIG>, in one embodiment, the turning vanes 20A, 20B, 20C, 20D are configured to turn the air path at least approximately <NUM>° within the supply conduit <NUM> and/or exhaust conduit <NUM>. It should be appreciated that in another embodiment, other geometries may be provided.

Turning now to <FIG> which illustrates a panel <NUM>, which may be used to make the walls of the through-air apparatus <NUM>. As shown in <FIG>, the through-air apparatus <NUM> may have a panelized construction including a plurality of panels <NUM>. As shown in <FIG> and <FIG>, the panels <NUM> may have a substantially rectangular or square shape. In one embodiment, the panels <NUM> are used to form both the external walls shown in <FIG>, as well as the internal walls shown in <FIG> which define the circuitous air path. The panelized construction is substantially different from a conventional through-air apparatus which is generally made of a traditional duct construction. Traditional duct construction may be undesirable because it typically requires large shipment sizes from the point of manufacture, and also because it may include a large amount of void volume during shipping due to the way a conventional duct is constructed. The inventors recognized that instead of individual duct sections mated together to make the air system conduit, these panels <NUM> may be used to make a pattern of panelized chambers to form the supply conduit <NUM> and exhaust conduit <NUM>. This may be advantageous for ease of fabrication, shipment and also for ease of installation. In the particular embodiment shown in <FIG>, the panel <NUM> includes an inner panel portion <NUM> and an outer panel portion <NUM>. Sandwiched between the inner and outer panel portions <NUM>, <NUM> is insulation <NUM> and a panel standoff <NUM> for rigidity. As mentioned above, in one embodiment there may be shared common walls between the supply conduit <NUM> and the exhaust conduit <NUM>. With respect to <FIG>, the inner panel portion <NUM> may act as a portion of the supply conduit <NUM>, whereas the outer panel portion <NUM> may act as a portion of the exhaust conduit <NUM>. It should be recognized that this may result in an overall compact through-air apparatus design.

Turning now to <FIG>, a comparison of the overall size of the through-air apparatus <NUM> in comparison to conventional systems will now be more fully described. As mentioned above, one of the advantages of the present disclosure is that the circuitous air path inside of the apparatus <NUM> enables the through-air apparatus to have a more compact configuration in comparison to a conventional through-air apparatus having a comparable air path length. <FIG> is a volume comparison of one embodiment of a through-air apparatus <NUM> compared to three conventional through-air bonder systems. As shown, the above-described through-air apparatus <NUM> has a smaller length, smaller width and a smaller height which also results in a much smaller volume. As shown in <FIG> and <FIG>, in one embodiment, the apparatus <NUM> has a substantially cubic shape.

It should be appreciated that in <FIG>, the dimensions of the illustrated boxes are rectangular cuboids (i.e. right rectangular prisms) that circumscribe the entire ducting system and its supports. The Cross-Machine Length (Length L shown in <FIG>) is the distance across the width of the web, or Tending Side to Drive Side of the projection of the system on the ground. This dimension may also be referred to as the Cross Direction Length. The Machine Direction Length ("MD", and also Width W shown in <FIG>) is the distance of the system's projection onto the ground in the direction of travel of the web being produced. The machine height is the height to the topmost part of the ducting system from the base elevation (Height H shown in <FIG>).

<FIG> is a front elevation comparison of one embodiment of a through-air apparatus <NUM> compared to three conventional through-air bonder systems. As shown, the above-described through-air apparatus <NUM> has a smaller width and height than the three conventional through-air bonder systems.

Finally, <FIG> is a footprint comparison (i.e. top view) of one embodiment compared to three conventional through-air bonder systems. As shown, the through-air apparatus <NUM> has a much more compact footprint due to its smaller length and width.

<FIG> is a chart which illustrates various dimensions and data for one embodiment compared to the three conventional bonder systems shown in <FIG>. The air path length is measured as the total distance a molecule of air must travel as it circulates through the air system along the centerline of the ducting network/conduit and completes one full circuit, thus returning to its point of origin. In one particular embodiment, the air path length of the above-described through-air apparatus <NUM> is approximately <NUM> meters. In the invention, the air path length is at least approximately <NUM> meters. In other examples, the air path length is at least approximately <NUM> meters, <NUM> meters, <NUM> meters, <NUM> meters, <NUM> meters, or <NUM> meters. It should be recognized that these lengths may be adequate to provide the above described high performance air flow requirements. Notably, the chart in <FIG> illustrates that for the through-air apparatus <NUM> of the invention, the ratio of the volume of the through-air apparatus to the length of the high flow circuitous air path is less than <NUM><NUM>. This is in contrast to Conventional Bonders A, B, and C for which the ratios of the volume of the through-air apparatus to the air path length are all between <NUM>-<NUM><NUM>. In particular, for Conventional Bonder A, this ratio of the volume of the through-air apparatus to the air path length is <NUM><NUM>, for Conventional Bonder B, this ratio of the volume of the through-air apparatus to the air path length is <NUM><NUM>, and finally, for Conventional Bonder C, this ratio of the volume of the through-air apparatus to the air path length is <NUM><NUM>.

It should be appreciated that in one example, the ratio of the volume of the through-air apparatus to the length of the high flow circuitous air path is less than <NUM><NUM>. In the invention, the ratio of the volume of the through-air apparatus to the length of the high flow circuitous air path is less than <NUM><NUM>. In other embodiments, the ratio of the volume of the through-air apparatus to the length of the high flow circuitous air path is less than <NUM><NUM>, <NUM><NUM>, or <NUM><NUM>. As shown in <FIG>, in one embodiment, the ratio of the volume of the through-air apparatus to the length of the high flow circuitous air path is approximately <NUM><NUM>.

Turning now to <FIG>, one embodiment of a through-air apparatus which includes an extraction conduit <NUM> in fluid communication with the high flow circuitous air path will now be described. As shown, the extraction conduit <NUM> includes an outlet <NUM> which is configured to extract air inside of the apparatus <NUM> to atmosphere. Extracting air to atmosphere may ensure a proper balance of the through-air apparatus. The amount of air extracted to atmosphere may be a function of the product permeability, combustion process and/or other variables.

The location of the extraction conduit <NUM> and how the air is being removed may impact the overall efficiency of the system. As shown, in this particular embodiment, the extraction conduit <NUM> is positioned proximate the exhaust conduit <NUM> which may minimize pressure losses within the circuitous air path. However in another embodiment, it is contemplated that the extraction conduit <NUM> is positioned adjacent another portion of the high flow circuitous air path, such as, but not limited to the supply conduit <NUM> and the through-air roll <NUM>.

As shown in the embodiment illustrated in <FIG>, there is a diverter <NUM> in the extraction conduit <NUM> which is configured to aid in the control of the amount of air that is extracted to atmosphere through the outlet <NUM>. In one embodiment, the diverter <NUM> is extendable and retractable into the exhaust conduit <NUM> to control the amount of air that is extracted to atmosphere. As shown in <FIG>, the diverter may include a curved portion and may, for example, be scoop-shaped to guide the air through the extraction conduit and to the outlet <NUM>. It is also contemplated that the diverter <NUM> may be configured to minimize pressure losses within the circuitous air path. As also shown in <FIG>, there may be a plurality of turning vanes <NUM> positioned within the extraction conduit <NUM> to guide the flow of air through the extraction conduit <NUM>, and further reducing pressure losses. Furthermore, as discussed above, a fan and/or a damper may be provided within the high flow circuitous air path to control the rate of air flow through the apparatus <NUM>.

<FIG> illustrates another embodiment of a through-air apparatus with an extraction conduit <NUM>. Many of the components shown in <FIG> are similar to the above-described components shown in <FIG>, and are thus given identical reference numbers. In this embodiment, the extraction conduit <NUM> includes a first outlet <NUM> which is configured to extract air inside of the apparatus to atmosphere. In this particular embodiment, the first outlet <NUM> is positioned on a rear side of the extraction conduit <NUM> in comparison to the outlet <NUM> shown in <FIG> which is positioned on a front side of the extraction conduit <NUM>. As shown, there may be a plurality of turning vanes <NUM> positioned within the extraction conduit to guide the flow of air through the extraction conduit <NUM> and out through the first outlet <NUM>. As shown in <FIG>, the turning vanes <NUM> may be angled or curved back towards the outlet <NUM> (this is in contrast to the turning vanes <NUM> shown in <FIG> which are angled forwards towards the outlet <NUM>).

In one embodiment, the extraction conduit <NUM> shown in <FIG> also includes a second outlet <NUM> configured for inspection inside of the apparatus. As shown in <FIG>, the second outlet <NUM> may include an inspection door which may be selectively opened by an operator to access inside of the circuitous air path. The inventors recognized that it may be desirable to have a second outlet <NUM> spaced apart from the first outlet <NUM> so that the inside of the apparatus may be inspected. As shown, the extraction conduit <NUM> may include a bifurcated conduit which includes the first outlet <NUM> and the second outlet <NUM>, and it is contemplated that the bifurcated conduit may be substantially T-shaped with the adjacent exhaust conduit <NUM>. It should also be appreciated that the first and second outlets <NUM>, <NUM> may be adapted for extraction of air to atmosphere out either or both of the first or second outlet <NUM>, <NUM>.

<FIG> illustrates one embodiment of a through-air apparatus, which is similar to the above described through-air apparatus shown in <FIG>, and thus similar components are given identical reference numbers. <FIG> further illustrates an external support system <NUM> coupled to the supply conduit <NUM> and the exhaust conduit <NUM> where the external support system <NUM> is configured to secure the supply conduit <NUM> and the exhaust conduit <NUM> to a ground surface <NUM>. As discussed above, the supply conduit <NUM> and the exhaust conduit <NUM> may have compact design with shared common walls. As discussed above and as shown in <FIG>, these supply and exhaust conduits <NUM>, <NUM> may be made of a plurality of panels <NUM> which form the exterior wall of the through-air apparatus <NUM>. It should be recognized that the inside of the supply conduit <NUM> and the exhaust conduit <NUM> are not visible in <FIG>. In this particular embodiment, the external support system <NUM> includes a plurality of vertical columns and horizontal beams which comprise a frame system that extends between the supply conduit <NUM> and the exhaust conduit <NUM> and the ground surface <NUM>. As mentioned below, in other embodiments other types of external support systems may be used. As shown in the embodiment illustrated in <FIG>, all load bearing surfaces from the supply conduit <NUM> and the exhaust conduit <NUM> to the external support system <NUM> are in a common horizontal plane <NUM>. As shown, the common horizontal plane <NUM> is substantially parallel to the ground surface <NUM>.

The inventors recognized that in contrast, in prior through-air apparatus designs, the load bearing surfaces of an air system (i.e. a supply conduit and an exhaust conduit) to an external support system were not all in a common horizontal plane. For example, in prior designs, load bearing surfaces were located in numerous planes. In prior designs, expansion relief joints were typically required at the load bearing surfaces to compensate for thermal growth in the through-air apparatus. The inventors recognized that this was undesirable. The inventors further recognized that one of the advantages of all of the load bearing surfaces of the supply conduit <NUM> and the exhaust conduit <NUM> to the external support system <NUM> being in a common horizontal plane <NUM> as shown in <FIG> is that it eliminates the need for expansion relief joints. The common horizontal plane <NUM> may also utilize a single central fixed support which minimizes the thermal expansion near the through-air roll <NUM>, which also reduces the required seal gap clearances around the roll <NUM> and improves process efficiency. It should be recognized that in another embodiment, other types of external support systems may be utilized with the above-mentioned unique common horizontal plane <NUM>, as the disclosure is not so limited.

In one illustrative embodiment shown in <FIG>, the through-air apparatus <NUM> also includes a cart <NUM> which is configured to receive the through-air roll <NUM>. As shown, the cart <NUM> may include a plurality of wheels <NUM> and the cart <NUM> is configured to slide out of the apparatus <NUM> (along the first axis <NUM>) to load the through-air roll <NUM> onto the cart <NUM>. Thereafter, the cart <NUM> and through-air roll <NUM> are configured to slide into the through-air apparatus. It should be appreciated that the cart <NUM> configuration may enable the through-air roll <NUM> to be more easily accessed for maintenance.

It should be appreciated that the specific type of through-air roll <NUM> may vary as the disclosure is not so limited. In one embodiment, the through-air roll <NUM> may be a trough style roll obtained from Valmet Inc. (see for example, <CIT>). In another embodiment, the through-air roll <NUM> may be configured differently, and may for instance, be a HONEYCOMB ROLL® obtained from Valmet, Inc.

Furthermore, as shown in <FIG>, in one illustrative embodiment, the through-air roll <NUM> has a single exhaust end which is coupled to the exhaust conduit <NUM>. It should also be recognized that the above described concepts may also be incorporated into a through-air apparatus that has a different exhaust configuration, including but not limited to a double exhaust end configuration. Additionally, although an axial exhaust configuration is shown in <FIG>, it is contemplated that the apparatus may include either axial or radial exhaust configurations.

Furthermore, one of ordinary skill in the art would recognize that in one embodiment, the above-described through-air apparatus may be used on a through-air bonder, and in another embodiment, the above-described through-air apparatus may be used on a through-air dryer, as the disclosure is not so limited.

Claim 1:
A high performance through-air apparatus (<NUM>) comprising:
a through-air roll (<NUM>) configured for rotational movement about a first axis (<NUM>);
a high flow air path inside of the apparatus that includes a path extending through a supply conduit (<NUM>), through the through-air roll (<NUM>), and also through an exhaust conduit (<NUM>);
a plurality of turning vanes (20a, 20b, 20c, 20d) positioned within the high flow circuitous path positioned to guide the flow of air through the apparatus;
wherein the through-air apparatus has a length, a width, a height, which together define a volume having a compact configuration; and
characterised in that the high flow air path inside of the apparatus is a high flow circuitous air path that has a length of at least <NUM>, wherein the ratio of the volume of the through-air apparatus to the length of the high flow circuitous air path is less than <NUM><NUM>.