WO1998022755A1

WO1998022755A1 - Ventilation device with air curtain effect

Info

Publication number: WO1998022755A1
Application number: PCT/KR1996/000208
Authority: WO
Inventors: Byong-Duk Kim
Original assignee: Kim Byong Duk
Priority date: 1996-11-21
Filing date: 1996-11-21
Publication date: 1998-05-28
Also published as: AU7656496A

Abstract

A ventilation device, using an air curtain effect while venting exhaust gas and heat into the atmosphere, is disclosed. An air chamber housing (13) is arranged around a heating area and has an air outlet slit on its top edge. In the chambre housing (13) a blower fan (14) sucks room air into the air chamber and expels the air upward from the chamber through the air outlet slit. An air injection nozzle body (18) is mounted to the chamber housing (13) in vicinity to the air outlet slit. The nozzle body (18) receives the air from the chamber and injects the air upward through its nozzle, thereby forming an air curtain around the heating area. The upward-injected curtaining air also effectively pushes the exhaust gas and heat into the exhaust duct, thus improving the ventilation effect of the device. The device does not generate any vortex and thereby effectively maintains the air curtain, and prevents diffusion of exhaust gas and heat into the environs of the heating area.

Description

VENTILATION DEVICE W ITH AIR CURTA IN EFFECT

Technical Field

The present invention relates, in general, to a ventilation device using an air curtain effect while venting and, more particularly, to a structural improvement in such a ventilation device for forcibly injecting pressurized room air through an upward nozzle thus effectively forming an air curtain around a heating area and thereby almost completely preventing diffusion of unhealthy burnt gas, odor and heat into the environs of the heating area w ith the air curtain effect.

B ackground A rt

A s well know n to those skilled in the art, a ventilation device is arranged above a roaster, a stove or a gas range in a home or restaurant in order to forcibly suck up and vent contaminated room air into the atmosphere thereby preventing diffusion of unhealthy burnt gas, odor and heat into the environs of the heating area. Such a ventilation device may also be used in a work area, such as a bonding work area or a toxic gas generating work area, thus preventing toxic gas from injuring the health of workers in such areas.

In a typical ventilation device, a fan is installed in the inlet port of an exhaust duct, which extends into the atmosphere through an exhaust pipe. However, in such a ventilation device, the diameter of the exhaust duct and the capacity of an exhaust fan are inevitably limited. The ventilation device thus only effectively exhausts the burnt gas and heat floating in vicinity to the inlet port of the duct. However, the device regrettably fails to remove the toxic burnt gas or heat, which does not reach the inlet port of the duct but has already been scattered into the environs of the heating area or the work area. The ventilation device thus causes a problem in that some of the toxic burnt gas or heat remains in room air and may injure one's health.

In an effort to overcome the above problems, Japanese Laid-open Publication Patent No. Sho. 48-6347 discloses "An air cleaning device with air curtain effect" (hereinbelow , referred to simply as "first prior embodiment"). The air cleaning device, according to the first prior embodiment, forms an air curtain around a heating area thus preventing diffusion of contaminated air into the environs of the heating area as shown in Fig. 2. In the above device, atmospheric fresh air is sucked into the room by an air conditioner, so that the device must be additionally provided with a heater for heating the cold fresh air to an appropriate temperature in w inter season. The device must be also provided w ith a cooler for cooling the hot fresh air to a temperature in summer season . Therefore, the device is problematic in that the heater and cooler force excessive costs on the owner.

In order to overcome the problems caused by the first prior embodiment, the inventor of this invention proposed "a ventilation device with air curtain effect" in Korean U.M .

Registration No. 97360 (hereinbelow, referred to simply as "second prior embodiment"). The device, according to the second prior embodiment, does not use outside air but uses room air while forming an air curtain around the heating area, so that the device is free from a heater or cooler for heating or cooling the air as shown in Fig. 1. As show n in Fig. 1, the ventilation device includes an exhaust duct 3, exhaust fan

6, suction fan 4, exhaust pipe 7 and curtaining air injection nozzle 8, which are the basic elements of a typical ventilation device with an air curtain effect. The device also includes an air circulation pipe 5a which passes in front and on opposite sides of the exhaust duct 3 in the device. In addition, a pressure chamber 5b is provided on the circulation pipe 5a. In operation of the above device, the curtaining air, which is sucked into the device by the suction fan 4, flows through both the circulation pipe 5a and the pressure chamber 5b and in turn is injected under pressure through the air injection nozzle 8, thus forming an air curtain around the heating area of, for example, a gas range 2. The air curtain skirts the boundary of the gas range 2, so that the gas or heat generated from the gas range 2 is prevented from diffusion into the environs of the gas range 2 but is effectively vented into the atmosphere through the exhaust pipe 7.

However, the ventilation device, according to the second prior embodiment, is problematic in that it must be additionally provided with both the circulation pipe 5a and the pressure chamber 5b, so that the device has a complex construction and thus is difficult to produce, and inflates the cost too much. Another problem of the above device resides in that the pressurized air sucked into the device by the suction fan 4 must pass through several passages, so that the pressure of the air is inevitably reduced. Therefore, the air injection pressure at the air injection nozzle 8 is not high enough to effectively form the air curtain around the heating area. In an effort to overcome the above problems, the inventor of this invention also proposed other types of ventilation devices with air curtain effect in Korean U.M . Registration Nos. 96-25288 and 96-25842 (hereinbelow, referred to simply as "third and fourth prior embodiments"). - A

In the device according to the fourth prior embodiment, the basic elements are common w ith those of the third prior embodiment, but a guide panel 9 is installed in the device in order to minimize the length of an air curtain forming mechanism. Therefore, only the construction and operation of the ventilation device according to the fourth prior embodiment will be described as follows.

The ventilation device, according to the fourth prior embodiment, includes an exhaust pipe 7' , exhaust duct 5', air chamber 3' , suction fan 4, exhaust fan 6' and curtaining air injection nozzle 8' , which are the basic elements of a typical ventilation device that uses an air curtain effect while venting. The above device somew hat successfully overcomes the problems caused by the device of the second prior embodiment. That is, the ventilation device of the fourth embodiment is easily produced, effectively reduces cost and maintains the pressure of sucked air and thereby effectively forms an air curtain around a heating area. However, the ventilation device according to the third or fourth prior is not free from the following problems which are commonly caused by the typical embodiments.

That is, the ventilation devices, according to the first to fourth prior embodiments, commonly have the following problems. In each of the above ventilation devices, the curtaining air is injected dow nward onto the boundary of a heating area while forming an air curtain around the heating area. Meanwhile, the burnt gas and heat, which are generated from the heating area and must be vented into the atmosphere, ascend to the ventilation device prior to being vented into the atmosphere. Therefore, the downward-injected curtaining air from the device inevitably interferes with the ascending gas and heat from the heating area, so that a vortex is generated between the curtaining air current and the burnt gas and heat current and thus regrettably breaks the air curtain. Particularly when such a vortex is generated while cooking or working with flame, the vortex agitates the flame and results in heat loss. In the above case, the burnt gas and heat may be not smoothly guided into the exhaust duct, but pass through the broken air curtain so as to be diffused into the environs of the heating area. Another problem of the above-mentioned ventilation devices resides in that the contaminated air or toxic materials existing in the exhaust duct may be injected into the room along with the dow nward-injected curtaining air.

D isclosure of the Inv ention

It is, therefore, an object of the present invention to provide a structurally-improved ventilation device in which the above problems can be overcome and which effectively forms an air curtain around a heating area without generating any vortex between the curtaining air current and the ascending burnt gas or heat current by injecting room air upward from a nozzle arranged around the heating area, and accelerates exhaust of burnt gas and heat into the atmosphere.

In order to accomplish the above object, the present invention provides a ventilation device using an air curtain effect while venting gas and heat into the atmosphere, comprising an exhaust duct which is arranged above an exhaust gas and heat source and extends into the atmosphere through an exhaust pipe. The exhaust duct is provided with an exhaust fan for forcibly pushing the gas and heat into the atmosphere. A n air chamber housing is arranged around the exhaust gas and heat source and has an air outlet slit on its top edge. The chamber housing also includes a blower fan which sucks room air into the interior of the chamber housing and exhausts the air upward from the chamber housing through the air outlet slit. An air injection nozzle body is mounted to the chamber housing in vicinity to the air outlet slit, and is adapted for receiving the air from the chamber housing and injecting the air upward in order to form an air curtain around the gas and heat source.

In the ventilation device, the exhaust duct is provided with a plurality of perforations and is surrounded by an outside duct with an opening being defined between the lower edges of the ducts. A vane extends inward and upw ard from the lower edge of the outside duct.

In accordance w ith the ventilation device of this invention, curtaining air is injected upward in order to form an air curtain while pushing the exhaust gas and heat into the exhaust duct thereby improving the ventilation effect. The device does not generate any vortex around the air curtain, thus effectively maintaining the air curtain and effectively preventing diffusion of exhaust gas and heat into the environs of a heating area.

Brief Description of the Draw ings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Figs. 1 and 2 are side-sectional views showing the operation of typical ventilation devices with an air curtain effect;

Fig. 3 is a side-sectional view showing the operation of a ventilation device in accordance with the primary embodiment of the present invention;

Fig. 4 is a partially-exploded perspective view showing the construction of an air chamber housing included in the ventilation device of this invention; Fig. 5 is a sectional view showing the construction of a curtaining air injection nozzle body included in the ventilation device of this invention;

Fig. 6 is a side-sectional view showing the operation of a ventilation device in accordance with another embodiment of the present invention ; and

Fig. 7 is a side- sectional view show ing the operation of a ventilation device in accordance w ith a further embodiment of the present invention.

Best Mode for Carrying Out the Invention

Fig. 3 is a side-sectional view showing the operation of a ventilation device in accordance with the primary embodiment of the present invention. As shown in the drawing, the ventilation device includes an air chamber housing 13, which comprises a box-shaped body opening at the top and is laid on, for example, a typical range holder 11. The bottom and side walls of the air chamber housing 13 are hollowed so as to define an air chamber. Seated in the top opening of the chamber housing 13 is a burnt gas and heat source, for example, a gas range 12. An exhaust duct 15, having an exhaust fan 16, is arranged above the gas range 12, with the hood of the duct 15 opening toward the range 12. A s show n in Figs. 3 and 4, a blower fan 14 is mounted inside the hollow bottom wall of the chamber housing 13. The fan 14 sucks room air into the air chamber and expels the air from the chamber in order to form an air curtain around the gas range 12. The outside top edge of each hollow side wall in the chamber housing 13 is stepped except for the corners and is longitudinally slitted in order to form an air outlet slit 13a. In addition, the top corners of the chamber housing 13 are provided with respective hinge holes 13b for movably seating a longitudinal nozzle body 18 in the step of each side wall. Opposite ends of the nozzle body 13b have respective hinge pins which are movably fitted into the hinge holes 13b. The longitudinal nozzle of the nozzle body 18 is narrower than the air ou tlet slit 13a of the cham ber housing 13.

In operation of the above ventilation device, the pneumatic pressure inside the air chamber housing 13 is increased due to the blowing force of the fan 14, so that room air is sucked into the housing 13. The pressurized air inside the housing 13 is guided into the nozzle bodies 18 through the air outlet slits 13a and in turn is injected upward through the longitudinal nozzles of the nozzle bodies 18, thus forming an air curtain around the gas range 12. The air from the nozzle bodies 18 in turn is guided into the exhaust duct 15 and is pushed into the atmosphere by the exhaust fan 16.

Due to the air curtain, the burnt gas and heat generated from the gas range 12 are effectively guided into the exhaust duct 15 and in turn are vented into the atmosphere. That is, the air curtain, which is formed around the gas range 12, effectively prevents diffusion of the burnt gas and heat into the environs of the gas range 12. The burnt gas and heat in the above state primarily ascend slowly from the gas range 12, but are accelerated by the pneumatic energy of the upward-injected air current of the air curtain when they reach the area around the inlet port of the exhaust duct 15, thereby being rapidly guided into the exhaust duct 15.

If briefly described, the curtaining air in the above ventilation device is injected in the same direction as that of exhaust gas and heat which are sucked up by the exhaust fan 16. Therefore, the curtaining air current does not interfere with the exhaust gas and heat current, so that the ventilation device does not generate any vortex between the two currents. The air curtain in the device is thus free from breaking. Another advantage of the device resides in that the contaminated air or toxic materials existing in the exhaust duct are not injected into the room because the curtaining air is injected upw ard different from the typical ventilation devices.

Fig. 5 shows the construction of the air injection nozzle body 18. As shown in the drawing, each nozzle body 18 is rotatably mounted to the chamber housing 13 by means of the hinge pins and holes 18a and 13b. When the ventilation device is not used, the nozzle bodies 18 are normally positioned in a stop position where the nozzles are directed sideward. However, during operation of the ventilation device, the nozzle bodies 18 are selectively rotated into an operating position where the nozzles are directed upward. When the nozzle bodies 18 are in their stop positions, the nozzles of the bodies 18 are effectively protected from, for example, dust. Another advantage of the rotatable construction of the nozzle bodies 18 resides in that it is possible to almost completely clean the air chamber housing 13 while rotating the bodies 18.

Fig. 6 shows the operation of a ventilation device in accordance with a second embodiment of the invention. In the second embodiment, the general shape of the ventilation device remains the same as in the primary embodiment, but a suction duct 21 is installed inside the exhaust duct 15 for promoting ventilation of burnt gas and heat into the atmosphere. The suction duck 21 extends dow nward from a position in vicinity of the exhaust fan 16 inside the exhaust duct 15 to a position around the space "A" above the gas range 12, so that the duct 21 directly connects the space "A" to the fan 16. Due to the suction duct 21, the burnt gas and heat floating in the space "A" are more smoothly and effectively guided to the exhaust fan 16. Fig. 7 show s the operation of a ventilation device in accordance w ith a third em bodiment of this invention. In the third embodimen t, the general shape of the ventilation device remains the same as in the primary embodiment, but the exhaust duct 25 is perforated in order to form a plurality of perforations 25a.

An exhaust fan 16 and a filter 22 are arranged in the perforated exhaust duct 25. The perforated exhaust duct 25 is surrounded by an outside duct 23 while forming an opening between the lower edges of the two ducts 23 and 25. The outside duct 23 has a vane 24, which extends inward and upward from the lower edge of the duct 23.

In operation of the ventilation device of Fig. 7, pressurized air, which is injected upward from the nozzle bodies 18 of the chamber housing 13, is guided into the space defined between the two ducts 23 and 25. While the air circulates inside the space between the two ducts 23 and 25, the air runs onto the top wall of the outside duct 23, so that the relatively-higher pressure of the air is reduced. The air with the reduced pressure in turn descends inside the outside duct 23 and is brought into contact with the ascending air injected from the nozzle bodies 18, so that a vortex is generated in the space between the two ducts 23 and 25. Due to the vortex, the injection pressure of the curtaining air from the nozzle bodies 18 is abruptly reduced.

Meanwhile, when air runs onto the top wall of the outside duct 23 and descends tow ard the opening defined between the two ducts 23 and 25, the descending air runs onto the upward vane 24 and is turned upward with reduced pressure. The low pressure air, which circulates inside the space between the two ducts 23 and 25, is smoothly guided into the exhaust duct 25 through the perforations 25a of the duct 25 and is effectively vented into the atmosphere.

In accordance w ith the ventilation device of the th ird embodiment, the pressure of the air injected from the air chamber housing 13 is reduced by the outside duct 23, so that the injected air from the chamber housing 13 is smoothly vented into the atmosphere. In operation of the above ventilation device, a reverse flow of the exhaust gas is almost completely prevented by the vane 24, so that the burnt gas and heat are more easily and smoothly vented into the atmosphere.

In home or factory, a heating area, which generates exhaust gas and heat, is typically arranged in a corner, so that it is not necessary to form the air curtain over all the boundary of the heating area. That is, the air curtain effectively prevents the exhaust gas and heat from diffusion into the environs of the heating area even if it is only formed on the open space around the area. W hen it is necessary for the ventilation device to partially form the air curtain on the open space around the heating area as described above, the ventilation device, which typically has a blower fan with a limited capacity, more effectively vents gas and heat into the atmosphere. In the above case, the corner walls in vicinity to the heating area may be isolated from the heating area by a shielding panel 26 as shown in Fig. 7.

As described above, the present invention provides a structurally-improved ventilation device with air curtain effect. In the ventilation device of this invention, room air is sucked into an air chamber by a blower fan and in turn is injected upward from the air injection nozzle of the chamber, thus effectively forming an air curtain around a heating area. The upward-injected air in the device flows in the same direction as that of exhaust gas and heat generated from the heating area. Therefore, the ventilation device does not generate any vortex between the curtaining air current and the exhaust gas and heat current and thereby is free from the problem in that the air curtain breaks by the vortex. The upward-injected air also accelerates exhaust of gas and heat into the atmosphere and thereby improves the operational effect of the ventilation device. Since room air is used for forming the air curtain, the air does not need to be heated or cooled in w inter or summer seasons different from typical ventilation devices.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A ventilation device using an air curtain effect while venting gas and heat into the atmosphere, comprising: an exhaust duct arranged above an exhaust gas and heat source and extending into the atmosphere through an exhaust pipe, said exhaust duct being provided with an exhaust fan for forcibly pushing the gas and heat into the atmosphere; an air chamber housing provided with an air outlet slit on its top edge and arranged around said exhaust gas and heat source, said chamber housing being provided with a blower fan for sucking room air into the interior of the chamber housing and exhausting the air upw ard from the chamber housing through the air outlet slit; and an air injection nozzle body mou nted to said cham ber housing in v icinity to the air outlet slit and adapted for receiving the air from the chamber housing and injecting the air upward in order to form an air curtain around the gas and heat source.

2. The ventilation device according to claim 1, wherein said exhaust duct is provided with a plurality of perforations and is surrounded by an outside duct with an opening being defined between the lower edges of said ducts, and a vane extending inward and upward from the lower edge of said outside duct.