Patent Description:
For an existing washer-dryer, based on heat exchange between an outer tub and the outside air, hot and humid air in the tub condenses on a tub wall to form condensed water, thereby achieving the effect of clothes drying. However, since there is a small temperature difference between the outer tub and the air in the tub, even if a blower is added between the outer tub and a case, the temperature difference between the outer tub and the air in the tub cannot be effectively reduced.

A related art discloses a washer-dryer. By adding a blower between an outer tub and a case, heat exchange between the outer tub and the outside air is improved, so that the outer tub is cooled, and based on a temperature difference between the inside and outside of the outer tub, the hot and humid air in the tub condenses, thus resulting in a high cost and a poor heat exchange effect.

For this reason, another related art discloses a cycle + suction + discharge washing machine. During circulation of airflow, part of the outside air can be sucked in through a suction opening, and then part of hot and humid air can be discharged from a discharge opening. However, at an initial stage of drying, because the blower will suck in the outside air, and then discharge part of the air out of the tub, and due to arrangement of a discharge opening, a passage for suction and discharge is formed on the one hand, which causes the direct discharge of hot air, thus resulting in a slow heating-up in the initial stage; on the other hand, the direct discharge of the hot and humid air in a later state will also affect the environment. Moreover, the risk of overfoaming may occur at both the suction opening and the discharge opening, and the risk of overfoaming is relatively high. <CIT> relates generally to a washer dryer in which a dryer is installed on top of the tub for heating and circulating air exhausted from a tub to dry clothes. <CIT> relates generally to a clothes treatment apparatus capable of increasing an effective air flow to clothes. <CIT> relates generally to a drying washing machine in which a fan draws the gas in an inner cylinder into a condensation chamber to condense, and guides it into a heating air duct to be heated by a heating device and then pumped into the inner cylinder to form a cycle to dry the clothes.

The present invention is intended to solve at least one of the technical problems existing in the prior art. In view of this, an objective of the present invention is to provide a clothes treatment device which has a simpler structure and high drying efficiency.

The clothes treatment device according to the invention includes:
a tub assembly defining a clothes treatment chamber therein, the tub assembly having an air inlet and an air outlet that are in communication with the clothes treatment chamber, the air inlet and the air outlet being provided at an upper part of a side wall of the tub assembly; and a clothes drying assembly including an air channel assembly communicating the air inlet with the air outlet, a heating member provided inside the air channel assembly, and a blower configured to guide air to flow, wherein the air channel assembly is provided with a vent in communication with the air outlet and the outside, and the vent is located above the air outlet.

In the clothes treatment device according to the embodiment of the present disclosure, a vent is provided and serves as an inlet/outlet of airflow to ensure a dynamic balance of air pressure between the clothes treatment chamber and the outside during the operation of the clothes treatment device. For example, when the air pressure in the clothes treatment chamber increases, part of the hot and humid air can overflow from the vent under the action of an air pressure difference, thus improving the drying efficiency; when the air pressure in the clothes treatment chamber decreases, the outside air can enter the clothes treatment chamber from the vent to participate in the circulation of the airflow, thereby realizing exchange of the hot and humid air with the outside air. In addition, compared with a technical solution with a discharge opening and a vent in the related art, by eliminating the discharge opening in the tub assembly, the clothes treatment device does not form a through airflow channel during the drying process, thereby ensuring quick heating-up in the tub assembly in the initial stage of the drying process and reducing the risk of overfoaming.

According to an embodiment of the present disclosure, a waterproof and air-permeable member is provided at the vent, thereby preventing water and foam in the clothes treatment chamber from overflowing from the vent, and ensuring that the air in the clothes treatment chamber can be discharged from the vent to the outside.

According to the invention, a flow area of the vent is within a rage of <NUM><NUM> to <NUM><NUM>.

According to an embodiment of the present disclosure, in an axial direction of the tub assembly, the air inlet is located at a front part of the tub assembly, and the air outlet is located at a rear part of the tub assembly.

According to an embodiment of the present disclosure, the flow area of the air outlet is greater than <NUM><NUM>.

According to an embodiment of the present disclosure, an orthographic projection of the air outlet on an imaginary horizontal plane passing through a central axis of the tub assembly deviates from the central axis of the tub assembly.

According to an embodiment of the present disclosure, the air channel assembly includes: an air channel shell mounted at the upper part of the side wall of the tub assembly, an inner cavity of the air channel shell being in communication with the air inlet; and a connecting base provided between the air channel shell and the tub assembly, the inner cavity of the air channel shell being in communication with the air outlet through an inner cavity of the connecting base, the vent being provided at the connecting base.

In some embodiments, a filter assembly and a spraying member are provided inside the connecting base, the filter assembly is configured to filter air discharged from the air outlet, and the spraying member is located above the filter assembly.

In some examples, the filter assembly includes a filter screen and an annular connecting frame, and the filter screen is mounted in the connecting base through the annular connecting frame.

In some embodiments, the air outlet is located below the connecting base, a bottom of the connecting base is defined with a first air-passing opening, and the first air-passing opening is in communication with the air outlet; a first latching rib is provided in a circumferential direction of one of the first air-passing opening and the air outlet, and a first latching groove fitted with the first latching rib is provided in a circumferential direction of the other one of the first air-passing opening and the air outlet.

In some embodiments, a filter screen and an annular connecting frame are connected in the connecting base, and the filter screen is mounted at the first air-passing opening through the annular connecting frame.

In some examples, a spraying member is further provided in the connecting base.

According to a further embodiment of the present disclosure, a bottom of the air channel shell is defined with a mounting opening, a top of the connecting base has a second air-passing opening, and the second air-passing opening is in communication with the mounting opening; a second latching rib is provided in a circumferential direction of one of the second air-passing opening and the mounting opening, and a second latching groove fitted with the second latching rib is provided in a circumferential direction of the other one of the second air-passing opening and the mounting opening.

According to a further embodiment of the present disclosure, an outer surface of the connecting base is provided with a connecting lug, an outer surface of the air channel shell is provided with a mounting lug, and the connecting base and the air channel shell are connected by a fastener passing through the connecting lug and the mounting lug.

According to a further embodiment of the present disclosure, the vent is provided to a side of the connecting base.

In some embodiments, the side of the connecting base is provided with a tube head protruding outwards, and the tube head extends in an up-down direction and is defined with the vent.

According to a further embodiment of the present disclosure, the air channel shell includes: an air channel base arranged above the tub assembly and the connecting base; an air channel cover plate covering a part of the air channel base; and a blower cover plate covering the other part of the air channel base, a fan of the blower being arranged between the blower cover plate and the air channel base.

In some embodiments, a side of the blower cover plate away from the air channel base is provided with a mounting recess recessed downwards for mounting a driving motor of the fan.

In some examples, a side wall of the mounting recess is provided with a plurality of spacer ribs arranged at intervals along a circumferential direction of the mounting recess for spacing at least a part of the driving motor apart from the side wall of the mounting recess. Each of the spacer ribs includes an inner rib section and an outer rib section connected to each other, the inner rib section is located in the mounting recess and extends along a depth direction of the mounting recess, and the plurality of outer rib sections are arranged in a radial way and located outside the mounting recess.

In some embodiments, a top of a side wall of the air channel base is defined with a groove extending in a circumferential direction, and one side of the air channel cover plate and the blower cover plate facing the air channel base are each provided with a protruding rib fitted with the groove.

The additional aspects and advantages of the present disclosure will be set forth in part in the following description and become apparent in part from the following description or be understood through the practice of the present disclosure.

The above-described and/or additional aspects and advantages of the present disclosure will become apparent and readily understood from the description of embodiments in conjunction with the following accompanying drawings, where.

Embodiments of the present disclosure will be described below in detail. Examples of the embodiments are illustrated in the accompanying drawings, where the same or similar reference numerals throughout the specification refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be illustrative only and are not to be construed as limiting the scope of the present disclosure.

A clothes treatment device <NUM> according to an embodiment of the present disclosure will be described below with reference to <FIG>. The clothes treatment device <NUM> here may be configured as a clothes dryer or a washer-dryer.

As shown in <FIG>, the clothes treatment device <NUM> according to the embodiment of the present disclosure includes a tub assembly <NUM> and a clothes drying assembly <NUM>.

The tub assembly <NUM> defines a clothes treatment chamber <NUM> therein. The tub assembly <NUM> has an air inlet <NUM> and an air outlet <NUM>. The air inlet <NUM> and the air outlet <NUM> are both in communication with the clothes treatment chamber <NUM>, and the air inlet <NUM> and the air outlet <NUM> are provided at an upper part of a side wall of the tub assembly <NUM>.

Further, the clothes drying assembly <NUM> includes an air channel assembly, a heating member <NUM> and a blower <NUM>. The air channel assembly communicates the air inlet <NUM> with the air outlet <NUM>. The air channel assembly has an air channel <NUM>, an air channel inlet of the air channel <NUM> is in communication with the air outlet <NUM>, and an air channel outlet <NUM> of the air channel <NUM> is in communication with the air inlet <NUM>.

The heating member <NUM> is arranged in the air channel <NUM> to heat air in the air channel <NUM>. In order to effectively utilize the space in the air channel <NUM>, improve drying efficiency, and increase a contact area between airflow and the heating member <NUM>, the heating member <NUM> is configured as a serpentine heating elbow. The blower <NUM> functions as a power component which forms airflow to guide air to flow. The air channel assembly has a vent <NUM> in communication with the air outlet <NUM> and the outside, and the vent <NUM> is located above the air outlet <NUM>.

In the clothes treatment device <NUM> according to the embodiment of the present invention, the vent <NUM> is provided and serves as an inlet/outlet of airflow to ensure a dynamic balance of air pressure between the clothes treatment chamber <NUM> and the outside during the operation of the clothes treatment device <NUM>. For example, when the air pressure in the clothes treatment chamber <NUM> increases, part of hot and humid air can overflow from the vent <NUM> under the action of an air pressure difference, thus improving the drying efficiency; when the air pressure in the clothes treatment chamber <NUM> decreases, the outside air can enter the clothes treatment chamber <NUM> from the vent <NUM> to participate in the circulation of the airflow, thereby realizing exchange of the hot and humid air with the outside air.

In addition, compared with a technical solution with a discharge opening and a vent in the related art, by eliminating the discharge opening in the tub assembly, the clothes treatment device <NUM> does not form a through airflow channel during the drying process, thereby ensuring quick heating-up in the tub assembly in an initial stage of the drying process and reducing the risk of overfoaming.

In order to prevent the water and foam in the clothes treatment chamber <NUM> from overflowing from the vent <NUM>, and to ensure that the air in the clothes treatment chamber <NUM> can be discharged from the vent <NUM> to the outside, a waterproof and air-permeable member is provided at the vent <NUM>. In this embodiment, the waterproof and air-permeable member is configured as a waterproof and air-permeable membrane. In some embodiments, the waterproof and air-permeable membrane may be made of a nylon material or a PET material.

As shown in <FIG> and <FIG>, in an axial direction of the tub assembly <NUM>, the air inlet <NUM> is located at a front part of the tub assembly <NUM>, and the air outlet <NUM> is located at a rear part of the tub assembly <NUM>. In other words, the air inlet <NUM> and the air outlet <NUM> are spaced apart in the axial direction of the tub assembly <NUM>.

Thus, a distance between the air inlet <NUM> and the air outlet <NUM> can be increased, i.e., a distance between the air channel inlet and the air channel outlet <NUM>, can be increased. In this way, the flowing time of moist air (discharged from the clothes treatment chamber <NUM>) in the air channel <NUM> can be increased, the heating time of the heating member <NUM> to the airflow is prolonged, and the moist air just discharged can be prevented from being sucked in immediately, which is beneficial to improving the drying efficiency.

In some embodiments, as shown in <FIG>, an orthographic projection of the air outlet <NUM> on an imaginary horizontal plane X passing through a central axis of the tub assembly <NUM> deviates from the central axis of the tub assembly <NUM>. Therefore, by effectively using the position of the tub assembly <NUM> in the circumferential direction, a distance between the air inlet <NUM> and the air outlet <NUM> can be increased, which is beneficial to improving the drying efficiency.

According to long-term experiments of the applicant, if the flow area of the vent <NUM> is too large, the hot air will leak out too quickly during the drying process of the clothes treatment device <NUM>, which will affect the drying efficiency and waste electrical energy; if the flow area of the vent <NUM> is too small, the moisture removal effect of the clothes treatment device <NUM> during the drying process will be too poor, which will affect the final moisture content and drying time.

As shown in <FIG>, in the present invention, by setting the flow area S0 of the vent <NUM> to be within a range of <NUM><NUM> and <NUM><NUM>, the hot air can be prevented from leaking too quickly, the energy consumption is low, and poor moisture removal effect can be avoided during the drying process, which is beneficial to improving the drying efficiency.

In order to ensure a high flowing efficiency of the airflow and faster heating-up of the tub assembly <NUM> to improve the drying efficiency, the flow area S2 of the air outlet <NUM> is set to be greater than <NUM><NUM>.

According to an embodiment of the present disclosure, the tub assembly <NUM> includes an outer tub <NUM> and an inner tub <NUM>. The inner tub <NUM> is rotatably provided in the outer tub <NUM> and extends along an axial direction of the outer tub <NUM>. The inner tub <NUM> defines a clothes treatment chamber 121in communication with a gap between the outer tub <NUM> and the inner tub <NUM>.

An air outlet <NUM> is provided at an upper part of a side wall of the outer tub <NUM> and is in communication with the clothes treatment chamber <NUM> through the gap. An air inlet <NUM> is provided on a front edge of the outer tub <NUM> or a door seal on the outer tub <NUM>. By arranging the air inlet <NUM> on the front edge of the outer tub <NUM>, the length of the air channel <NUM> can be increased, thereby improving the drying efficiency; by arranging the air inlet <NUM> on the door seal on the outer tub <NUM>, the length of the air channel <NUM> can be increased and the drying efficiency is accordingly improved on the one hand, and on the other hand, there is no need to form holes in the outer tub <NUM>, which simplifies the structure and processing procedures of the outer tub <NUM> and reduces the cost.

As shown in <FIG>, according to an embodiment of the present disclosure, the air channel assembly includes an air channel shell <NUM> mounted at the upper part of the side wall of the tub assembly <NUM>, and an inner cavity of the air channel shell <NUM> is in communication with the air inlet <NUM>. In this embodiment, the air channel shell <NUM> is mounted at the top of the outer tub <NUM>, and at least a part of the air channel shell <NUM> extends along the axial direction of the tub assembly <NUM>.

Further, the air channel assembly further includes a connecting base <NUM> provided between the air channel shell <NUM> and the tub assembly <NUM>, so as to communicate the inner cavity of the air channel shell <NUM> with the air outlet <NUM>, that is, the inner cavity of the connecting base <NUM> and the inner cavity of the air channel shell <NUM> constitute an air channel <NUM>, and the vent <NUM> is provided on the connecting base <NUM>. In this embodiment, the connecting base <NUM> is provided between an air channel base <NUM> of the air channel shell <NUM> and the outer tub <NUM>, which can not only support the air channel base <NUM>, but also effectively utilize the top space of the outer tub <NUM> to facilitate communication with the outside.

In some embodiments, the air channel shell <NUM> includes an air channel base <NUM>, an air channel cover plate <NUM>, and a blower cover plate <NUM>. The air channel cover plate <NUM> covers a part of the air channel base <NUM>, and the air channel cover plate <NUM> and the air channel base <NUM> define a part of the air channel <NUM>. The blower cover plate <NUM> covers the other part of the air channel base <NUM>, and the blower cover plate <NUM> and the air channel base <NUM> define the other part of the air channel <NUM>. It can be understood that, in this embodiment, the connecting base <NUM> defines the rest part of the air channel <NUM>.

As shown in <FIG> and <FIG>, the blower <NUM> includes a fan <NUM> and a driving motor <NUM> for driving the fan <NUM> to rotate. The fan <NUM> of the blower <NUM> is provided between the blower cover plate <NUM> and the air channel base <NUM>, and the driving motor <NUM> is provided outside the blower cover plate <NUM>.

In this embodiment, a side of the blower cover plate <NUM> away from the air channel base <NUM> has a downwardly recessed mounting recess <NUM> for mounting the driving motor <NUM>, and a motor shaft of the driving motor <NUM> passes through a bottom wall of the mounting recess <NUM> so as to be connected to the fan <NUM>.

In some examples, a side wall of the mounting recess <NUM> is provided with a plurality of spacer ribs <NUM> arranged at intervals along the circumferential direction of the mounting recess <NUM>. The spacer ribs <NUM> can space at least a part of the driving motor <NUM> from the side wall of the mounting recess <NUM>; in this way, a limiting effect can be achieved and a gap between the driving motor <NUM> and the mounting recess <NUM> can also be ensured, thus facilitating heat dissipation.

As shown in <FIG>, each spacer rib <NUM> includes an inner rib section <NUM> and an outer rib section <NUM> that are connected to each other. The inner rib section <NUM> is located in the mounting recess <NUM> and extends along a depth direction of the mounting recess <NUM>. One end of the outer rib section <NUM> is connected to an upper end of the inner rib section <NUM> and is located outside the mounting recess <NUM>. The plurality of outer rib sections <NUM> are arranged in a radial way, which is beneficial to improving the structural strength of the blower cover plate <NUM>.

In some embodiments, the top of the side wall of the air channel base <NUM> has a groove <NUM> extending along its circumferential direction, and one sides of the air channel cover plate <NUM> and the blower cover plate <NUM> facing the air channel base <NUM> are each provided with a protruding rib <NUM> fitted with the groove <NUM>, thus ensuring the reliability and tightness of the connection between the air channel base <NUM> and the air channel cover plate <NUM> and between the air channel base <NUM> and the blower cover plate <NUM>.

Further, the groove <NUM> is provided inside with a sealing ring extending along its circumferential direction. When the protruding rib <NUM> is fitted with the groove <NUM>, the sealing ring is pressed tightly, thereby further ensuring the tight connection between the air channel base <NUM> and the air channel cover plate <NUM> and between the air channel base <NUM> and the blower cover plate <NUM>.

In some embodiments, a filter assembly (not shown) and a spraying member <NUM> are connected in the connecting base <NUM>. The filter assembly is configured to filter the hot and humid air discharged from the air outlet <NUM> to prevent lint of clothes from entering the air channel <NUM>. The spraying member <NUM> can wash the filter assembly, thereby flushing the lint on the filter assembly back to the clothes treatment chamber <NUM> to prevent the accumulation of lint.

In some examples, the filter assembly includes a filter screen and an annular connecting frame <NUM>. The filter screen is mounted in the connecting base <NUM> through the annular connecting frame <NUM>. The annular connecting frame <NUM> can not only fix the filter screen, but also improve the structural strength of the connecting base <NUM>.

In this embodiment, the bottom of the connecting base <NUM> is provided with a first air-passing opening <NUM>, and the filter screen is fixed at the first air-passing opening <NUM> by the annular connecting frame <NUM>. The filter screen can filter the hot and humid air discharged from the air outlet <NUM> to prevent the lint of clothes from entering the air channel <NUM>. Moreover, the filter screen can also increase the resistance of foam entering the air channel <NUM>. In addition, compared with the technical solution of directly installing the filter screen on the air outlet in the related art, the solution of installing the filter screen and the annular connecting frame <NUM> in the connecting base <NUM> facilitates the modularization of components and also facilitates the assembly and disassembly of the filter screen.

According to a further embodiment of the present disclosure, the air outlet <NUM> is located below the connecting base <NUM>, and the bottom of the connecting base <NUM> has a first air-passing opening <NUM> in communication with the air outlet <NUM>, that is, the first air-passing opening <NUM> forms an air channel inlet of the air channel <NUM>. A first latching rib <NUM> is provided in the circumferential direction of one of the first air-passing opening <NUM> and the air outlet <NUM>, and a first latching groove <NUM> fitted with the first latching rib <NUM> is provided in the circumferential direction of the other one, thus ensuring the reliability and tightness of the connection between the tub assembly <NUM> and the connecting base <NUM>.

As shown in <FIG>, in this embodiment, a first latching groove <NUM> is provided in the circumferential direction of the first air-passing opening <NUM> and forms a ring around the first air-passing opening <NUM>, and a first latching rib <NUM> is provided in the circumferential direction of the air outlet <NUM> and surrounds the air outlet <NUM>. By the fitting of the first latching rib <NUM> and the first latching groove <NUM> realizes a reliable connection between the connecting base <NUM> and the outer tub <NUM>. In order to further ensure the airtightness between the connecting base <NUM> and the outer tub <NUM>, a sealing ring may be provided in the first latching groove <NUM>, and the sealing ring is pressed tightly when the first latching rib <NUM> and the first latching groove <NUM> are fitted.

According to a further embodiment of the present disclosure, a bottom of the air channel shell <NUM> has a mounting opening <NUM>, a top of the connecting base <NUM> has a second air-passing opening <NUM>, and the second air-passing opening <NUM> is in communication with the inner cavity of the air channel shell <NUM>; a second latching rib <NUM> is provided in a circumferential direction of one of the second air-passing opening <NUM> and the mounting opening <NUM>, and a second latching groove <NUM> fitted with the second latching rib <NUM> is provided in the circumferential direction of the other one.

As shown in <FIG>, in this embodiment, a second latching rib <NUM> is provided in the circumferential direction of the second air-passing opening <NUM> and surrounds the second air-passing opening <NUM>, and a second latching groove <NUM> is provided in the circumferential direction of the mounting opening <NUM> and surrounds the mounting opening <NUM>. By the fitting of the second latching rib <NUM> and the second latching groove <NUM> realizes a reliable connection between the connecting base <NUM> and the air channel base <NUM>. In order to further ensure the airtightness between the connecting base <NUM> and the air channel base <NUM>, a sealing ring may be provided in the second latching groove <NUM>, and the sealing ring is pressed tightly when the second latching rib <NUM> and the second latching groove <NUM> are fitted.

As shown in <FIG>, an outer surface of the connecting base <NUM> is provided with a connecting lug <NUM>, and an outer surface of the air channel shell <NUM> is provided with a mounting lug <NUM>. The connecting base <NUM> and the air channel shell <NUM> are connected reliably and stably by a fastener passing through the connecting lug <NUM> and the mounting lug <NUM>. In this embodiment, the air channel base <NUM> has a side coaming extending along its circumferential direction, the mounting lug <NUM> is provided on the side coaming, the connecting base <NUM> and the air channel base <NUM> are further connected by a fastener passing through connecting holes in the connecting lug <NUM> and the mounting lug <NUM>.

In some embodiments, the vent <NUM> is provided on a side of the connecting base <NUM>. Specifically, the side of the connecting base <NUM> is provided with a protruding tube head <NUM> and the tube head <NUM> extends in an up-down direction and thus defines the vent <NUM>. The advantages of simple structure and easy processing and manufacturing are achieved.

In this embodiment, the connecting base <NUM> includes a body part and a cover plate part. The body part is provided with a first air-passing opening <NUM> at the bottom and a second air-passing opening <NUM> at the top, and a side of the body part is provided with an opening. The cover plate part is provided at the opening, and a side of the cover plate part away from the body part is provided with a tube head <NUM>, thus defining a vent <NUM>.

In the description of the present disclosure, it is to be understood that the orientations or positional relationships, indicated by the terms "central", "longitudinal", "lateral", "length", "width", "thickness", "on", "under", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, are based on the orientations or positional relationships shown in the drawings and are only for the purpose of facilitating and simplifying the description of the present disclosure, rather than indicating or implying that the described device or element must have a particular orientation or must be constructed and operated in a particular orientation, and therefore they cannot to be construed as limiting the present disclosure.

Other configurations and operations of the clothes treatment device <NUM> according to the embodiment of the present disclosure are known to those of ordinary skill in the art, and will not be described in detail here.

Claim 1:
A clothes treatment device (<NUM>), comprising:
a tub assembly (<NUM>) defining a clothes treatment chamber (<NUM>) therein, the tub assembly (<NUM>) having an air inlet (<NUM>) and an air outlet (<NUM>) that are in communication with the clothes treatment chamber (<NUM>), the air inlet (<NUM>) and the air outlet (<NUM>) being provided at an upper part of a side wall of the tub assembly (<NUM>); and
a clothes drying assembly (<NUM>) comprising an air channel assembly communicating the air inlet (<NUM>) with the air outlet (<NUM>), a heating member (<NUM>) provided inside the air channel assembly, and a blower (<NUM>) configured to guide air to flow,
wherein the air channel assembly is provided with a vent (<NUM>) in communication with the air outlet (<NUM>) and outside, and the vent (<NUM>) is located above the air outlet (<NUM>);
characterised in that a flow area (S0) of the vent (<NUM>) is within a range of <NUM><NUM> to <NUM><NUM>.