BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to an exhaust hood, and, more particularly, to an exhaust
hood that allows flow of air to be changed based on the user's circumstances for selectively
accomplishing air-curtain effect and Coanda effect, whereby the convenience of the
exhaust hood is improved.
Description of the Related Art
[0002] Each kitchen is generally provided with a cooking table, on which a heating unit,
such as an electric heater or a gas cooker, for applying heat to food such that the
food is cooked, for example, boiled or baked, is disposed.
[0003] When food is cooked at high temperature generated by the heating unit disposed on
the cooking table, the food gives off odors. The odors are generated by oil particles
and aerosol particles floating in the air while the food is cooked. Especially in
a poorly ventilated kitchen, the odors generated from the food may prevent the chef
from concentrating and may thus cause injury. For this reason, an exhaust hood is
disposed above the cooking table for exhausting the odors and contaminated substances.
[0004] FIG. 1 is a view schematically showing a conventional exhaust hood 10 for kitchens.
[0005] As shown in FIG. 1, the conventional exhaust hood 10 for kitchens is disposed above
a cooking table 2, on which food is cooked, while being fixed to a mounting wall 4
and a ceiling 6.
[0006] The exhaust hood 10 comprises: a hood body 12 forming the appearance of the exhaust
hood 10, the hood body 12 being provided with an inlet port 14 and an outlet port
16; an exhaust fan 18 for suctioning air into the hood body 12 and discharging the
air out of the kitchen; a motor (not shown) for driving the exhaust fan 18; a filter
20 disposed in the inlet port 14 of the hood body 12 for purifying air when the air
is suctioned through the inlet port 14; and an exhaust pipe (not shown) connected
to the outlet port 16 of the hood body 12 for guiding air discharged through the outlet
port 16 out of the kitchen.
[0007] The operation of the conventional exhaust hood with the above-stated construction
will now be described.
[0008] When the exhaust hood 10 is operated while food is cooked on the cooking table 2,
the exhaust fan 18 is rotated by the motor. As a result, contaminated air generated
while the food is cooked, such as gas and grease fumes, is introduced into the hood
body 12 through the inlet port 14 by a suction force of the exhaust fan 18.
[0009] As it is introduced into the hood body 12 through the inlet port 14, the contaminated
air passes through the filter 20, by which the contaminated substances are filtered
out. Consequently, the purified air is discharged out of the kitchen through the outlet
port 16 and the exhaust pipe.
[0010] With the conventional exhaust hood, however, air present in front of the inlet port
14 or at both sides of the inlet port 14 is not satisfactorily suctioned into the
hood body 12 although air present below the inlet port 14 of the hood body 12 is satisfactorily
suctioned into the hood body 12. As a result, contaminated air diffuses throughout
the kitchen.
[0011] In order to solve the above problem, the other fan is disposed in front of the hood
body of the exhaust hood for injecting air in front of the cooking table to isolate
a user from the cooking table (air-curtain effect), or the hood body of the exhaust
hood is modified such that the front end of the hood body is curved to cause air to
flow along the curved front end of the hood body (Coanda effect). In this way, the
suction force and collecting efficiency in front of the exhaust hood are improved.
[0012] In this case, however, either the air-curtain effect or the Coanda effect is individually
used, and therefore, the efficiency of the exhaust hood is limited.
SUMMARY OF THE INVENTION
[0013] Therefore, the present invention has been made in view of the above problems, and
it is an object of the present invention to provide an exhaust hood that is capable
of effectively collecting contaminated air generated at a cooking table in a kitchen
for preventing the contaminated air from diffusing about the kitchen and other dwelling
areas.
[0014] In accordance with the present invention, the above and other objects can be accomplished
by the provision of an exhaust hood comprising: a hood body disposed above a cooking
table in a kitchen, the hood body being provided with an inlet port and an outlet
port; an exhaust fan mounted to one side in the hood body for suctioning air into
the hood body through the inlet port and discharging the air out of the kitchen through
the outlet port; an auxiliary fan mounted to the other side in the hood body; a nozzle
unit disposed at the front part of the hood body for discharging air blown by the
auxiliary fan into the kitchen; a guide unit mounted to the nozzle unit, the guide
unit having a curved part for guiding air such that air around the curved part of
the guide unit flows along the curved part of the guide unit; and an air flow changing
unit disposed between the nozzle unit and the guide unit such that the air flow changing
unit can be rotated along the curved part of the guide unit for changing flow of air
discharged from the nozzle unit.
[0015] Preferably, the air flow changing unit comprises: a louver disposed in the nozzle
unit while being spaced a predetermined distance from the guide unit, the louver and
the guide unit together defining a discharging slit therebetween such that air is
discharged from the nozzle unit through the discharging slit.
[0016] Preferably, the air flow changing unit further comprises: a motor for rotating the
louver.
[0017] Preferably, the louver comprises: a guide part for guiding flow of air; and connection
parts attached to both ends of the guide part, the connection parts being connected
to a rotary shaft of the motor.
[0018] Preferably, the guide unit is a ring-shaped rod mounted to a lower part of the nozzle
unit.
[0019] Preferably, the ring-shaped rod is formed in a hollow shape such that the motor is
mounted in the ring-shaped rod.
[0020] Preferably, the air flow changing unit is provided with at least one roller that
is in rolling contact with the curved part of the guide unit.
[0021] Preferably, the at least one roller comprises: a plurality of rollers attached to
the lower surface of the air flow changing unit while being spaced a predetermined
length from each other in the longitudinal direction thereof.
[0022] Preferably, the rollers are rotatably connected to the air flow changing unit.
[0023] Preferably, the hood body is provided with an auxiliary inlet port, the auxiliary
inlet port being disposed the auxiliary fan for allowing air to be introduced into
the hood body therethrough by the auxiliary fan.
[0024] According to the present invention, the flow of air discharged from the nozzle unit
out of the kitchen is changed by the guide unit and the air flow changing unit disposed
in the nozzle unit of the hood body. Consequently, the present invention has the effect
of selectively accomplishing an air-curtain effect for preventing contaminated air
from diffusing in front of the cooking table and a Coanda effect for collecting contaminated
air away from the inlet port of the hood body, and therefore, improving the convenience
of the exhaust hood.
[0025] Also, the number of rotations of the auxiliary fan can be changed such that the number
of rotations of the auxiliary fan is increased to increase the speed of the nozzle
unit for accomplishing the air-curtain effect, and the number of rotations of the
auxiliary fan is decreased to decrease the speed of the nozzle unit for accomplishing
the Coanda effect. Consequently, the present invention has the effect of more efficiently
accomplishing the air-curtain effect and the Coanda effect.
[0026] Also, the contaminated air is collected irrespective of the performance of the exhaust
fan. Consequently, the present invention has the effect of improving collection efficiency.
[0027] Also, the guide unit is a ring-shaped rod mounted to the nozzle unit, the air flow
changing unit comprises a louver disposed in the nozzle unit while being spaced a
predetermined distance from the ring-shaped rod, and the louver is rotated by the
stepping motor. Consequently, the present invention has the effect of easily controlling
the position of the louver and easily operating the louver.
[0028] Furthermore, the air flow changing unit is provided with a plurality of rollers,
which are in rolling contact with the curved part of the guide unit. Consequently,
the present invention has the effect of preventing the air flow changing unit from
being lowered, maintaining the balance of the air flow changing unit, and reducing
friction between the air flow changing unit and the guide unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] 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:
FIG. 1 is a view schematically showing a conventional exhaust hood for kitchens;
FIG. 2 is a sectional view showing an exhaust hood for kitchens according to a preferred
embodiment of the present invention;
FIG. 3 is a view schematically illustrating air-curtain effect of the exhaust hood
for kitchens according to a preferred embodiment of the present invention shown in
FIG. 2; and
FIG. 4 is a view schematically illustrating Coanda effect of the exhaust hood for
kitchens according to a preferred embodiment of the present invention shown in FIG.
2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Now, a preferred embodiment of the present invention will be described in detail
with reference to the accompanying drawings.
[0031] FIG. 2 is a sectional view showing an exhaust hood for kitchens according to a preferred
embodiment of the present invention, FIG. 3 is a view schematically illustrating air-curtain
effect of the exhaust hood for kitchens according to a preferred embodiment of the
present invention shown in FIG. 2, and FIG. 4 is a view schematically illustrating
Coanda effect of the exhaust hood for kitchens according to a preferred embodiment
of the present invention shown in FIG. 2.
[0032] As shown in FIGS. 2 to 4, the exhaust hood according to the present invention comprises:
a hood body 50 disposed above a cooking table (not shown), the hood body 50 being
provided with an inlet port 52 and an outlet port 54; an exhaust fan 56 mounted to
one side in the hood body 50 for suctioning air into the hood body 50 through the
inlet port 52 and discharging the air out of the kitchen through the outlet port 54;
an auxiliary fan 58 mounted to the other side in the hood body 50; a nozzle unit 60
disposed at the front part of the hood body 50 for discharging air blown by the auxiliary
fan 58 into the kitchen; a guide unit mounted to the nozzle unit 60, the guide unit
having a curved part for guiding air such that air around the curved part of the guide
unit flows along the curved part of the guide unit; and an air flow changing unit
70 disposed between the nozzle unit 60 and the guide unit such that the air flow changing
unit 70 can be rotated along the curved part of the guide unit for changing flow of
air discharged from the nozzle unit 60.
[0033] In the inlet port 52 is mounted a filter 53 for purifying air when the air is suctioned
through the inlet port 52. To the outlet port 54 is connected an exhaust pipe (not
shown), which forms a passage through which the suctioned air is discharged out of
the kitchen.
[0034] In the hood body 50 is mounted an exhaust fan motor (not shown) for driving the exhaust
fan 56.
[0035] The auxiliary fan 58 may be a cross-flow fan or a thin centrifugal fan. The auxiliary
fan 58 is configured such that the number of rotations of the auxiliary fan 58 can
be changed.
[0036] At the hood body 50 is formed an auxiliary inlet port 64 for allowing air to be introduced
into the hood body 50 therethrough. The auxiliary inlet port 64 is disposed above
the auxiliary fan 58.
[0037] In the illustrated embodiment, the auxiliary inlet port 64 is disposed above the
auxiliary fan 58, although the auxiliary fan 58 may suction air through the filter
53 mounted in the inlet port 52 and blow the air to the nozzle unit 60.
[0038] The guide unit is a ring-shaped rod 62 mounted to a lower part 61 of the nozzle unit
60. An upper part 63 of the nozzle unit 60 is curved by a predetermined length such
that the upper part 63 of the nozzle unit 60 corresponds to the outer circumferential
surface of the ring-shaped rod 62.
[0039] The air flow changing unit 70 comprises: a louver 72 disposed in the nozzle unit
60 while being spaced a predetermined distance from the ring-shaped rod 62; and a
motor 74 for rotating the louver 72.
[0040] Between the louver 72 and the ring-shaped rod 62 is defined a discharging slit 80,
through which air having passed through the nozzle unit 60 from the auxiliary fan
58 is discharged.
[0041] The louver 72 comprises: a guide part 82 for guiding flow of air; and connection
parts 84 attached to both ends of the guide part 82, the connection parts 84 being
connected to a rotary shaft 75 of the motor 74.
[0042] Preferably, the motor 74 is a stepping motor that is capable of controlling the rotation
angle of the louver 72.
[0043] The ring-shaped rod 62 is formed in a hollow shape such that the motor 74 is mounted
in the ring-shaped rod 62. The rotary shaft 75 of the motor 74 extends in the longitudinal
direction of the ring-shaped rod 62.
[0044] The connection parts 84 are bent from both ends of the guide part 82 toward the ring-shaped
rod 62 such that the connection parts 84 are connected to the rotary shaft 75 of the
motor 74.
[0045] The louver 72 is provided with at least one roller 76 that is in rolling contact
with the outer circumferential surface of the ring-shaped rod 62. Preferably, a plurality
of rollers 76 are attached to the lower surface of the louver 72 while being spaced
a predetermined length from each other in the longitudinal direction thereof.
[0046] Specifically, the rollers 76 are rotatably connected to the connection members 78
formed at the lower surface of the louver 72 while extending toward the rollers 76.
At the connection members 78 are formed insertion holes, through which rotary shafts
77 of the rollers 76 are inserted, respectively.
[0047] The operation of the exhaust hood with the above-stated construction according to
the present invention will now be described.
[0048] When the exhaust fan 56 is operated while food is cooked on the cooking table, contaminated
air in the kitchen is introduced into the hood body 50 through the inlet port 52,
and is then discharged out of the kitchen through the outlet port 54.
[0049] At this time, the auxiliary fan 58 may be operated either to interrupt flow of air
between a user and the cooling table (air-curtain effect) or to guide flow of air
such that the air flows along the ring-shaped rod 62 for improving collecting efficiency
at the inlet port 52 (Coanda effect).
[0050] To accomplish the air-curtain effect, the motor 74 is operated to rotate the louver
72 such that the louver 72 is placed at the front end of the nozzle unit 60.
[0051] When the motor 74 is operated, the louver 72 is rotated toward the front end of the
nozzle unit 60 about the rotary shaft 75 of the motor 74.
[0052] When the louver 72 is moved forward along the ring-shaped rod 62 by the roller 76,
and therefore, the upper side of the louver 72 is placed at the end of the upper part
63 of the nozzle unit 60, the operation of the motor 74 is stopped.
[0053] As a result, the discharging slit 80 defined between the louver 72 and the ring-shaped
rod 62 is horizontally located, and therefore, air blown by the auxiliary fan 58 is
vertically discharged downward toward the cooking table through the discharging slit
80.
[0054] At this time, it is preferable that the number of rotations of the auxiliary fan
58 be increased to increase the speed of the nozzle unit 60.
[0055] The air vertically discharged downward from the discharging slit 80 isolates the
user from the cooking table, and therefore, smoke or odor generated during cooking
is prevented from diffusing in front of the cooking table.
[0056] To accomplish the Coanda effect, the motor 74 is operated to rotate the louver 72
such that the louver 72 is placed at the top of the ring-shaped rod 62.
[0057] As a result, the discharging slit 80 defined between the louver 72 and the ring-shaped
rod 62 is located at the top of the ring-shaped rod 62, and therefore, air blown by
the auxiliary fan 58 is discharged, while being tilted, to the top surface of the
ring-shaped rod 62.
[0058] At this time, it is preferable that the number of rotations of the auxiliary fan
58 be decreased to decrease the speed of the nozzle unit 60 to approximately 5 m/s.
[0059] The air discharged, while being tilted, to the top surface of the ring-shaped rod
62 flows along the outer circumferential surface of the ring-shaped rod 62. As a result,
negative pressure is created around the ring-shaped rod 62.
[0060] The phenomenon in which fluid flows along a curve is called the Coanda phenomenon,
which is caused due to viscosity of fluid.
[0061] As the negative pressure is created around the ring-shaped rod 62, air away from
the hood body 50 is collected to the inlet port 52 along the bottom surface of the
ring-shaped rod 62.
[0062] Specifically, contaminated air away from the inlet port 52 of the hood body 50 is
suctioned into the inlet port 52, and therefore, collection efficiency is improved.
[0063] As described above, the air-curtain effect and the Coanda effect are selectively
used by changing the position of the louver 72 based on the user's circumstances.
[0064] As apparent from the above description, the flow of air discharged from the nozzle
unit out of the kitchen is changed by the guide unit and the air flow changing unit
disposed in the nozzle unit of the hood body. Consequently, the present invention
has the effect of selectively accomplishing air-curtain effect of preventing contaminated
air from diffusing in front of the cooking table and Coanda effect of collecting contaminated
air away from the inlet port of the hood body, and therefore, improving the convenience
of the exhaust hood.
[0065] Also, the number of rotations of the auxiliary fan can be changed such that the number
of rotations of the auxiliary fan is increased to increase the speed of the nozzle
unit for accomplishing the air-curtain effect, and the number of rotations of the
auxiliary fan is decreased to decrease the speed of the nozzle unit for accomplishing
the Coanda effect. Consequently, the present invention has the effect of more efficiently
accomplishing the air-curtain effect and the Coanda effect.
[0066] Also, the contaminated air is collected irrespective of the performance of the exhaust
fan. Consequently, the present invention has the effect of improving the collection
efficiency.
[0067] Also, the guide unit is a ring-shaped rod mounted to the nozzle unit, the air flow
changing unit comprises a louver disposed in the nozzle unit while being spaced a
predetermined distance from the ring-shaped rod, and the louver is rotated by the
stepping motor. Consequently, the present invention has the effect of easily controlling
the position of the louver and easily operating the louver.
[0068] Furthermore, the air flow changing unit is provided with a plurality of rollers,
which are in rolling contact with the curved part of the guide unit. Consequently,
the present invention has the effect of preventing the air flow changing unit from
being lowered, maintaining the balance of the air flow changing unit, and reducing
friction between the air flow changing unit and the guide unit.
[0069] Although the preferred embodiment of the present invention has 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.
1. An exhaust hood comprising:
a hood body (50) disposed above a cooking table in a kitchen, the hood body (50) being
provided with an inlet port (52) and an outlet port (54);
an exhaust fan (56) mounted to one side in the hood body (50) for suctioning air into
the hood body (50) through the inlet port (52) and discharging the air out of the
kitchen through the outlet port (54);
an auxiliary fan (58) mounted to other side in the hood body (50);
a nozzle unit (60) disposed at the front part of the hood body (50) for discharging
air blown by the auxiliary fan (58) into the kitchen;
a guide unit mounted to the nozzle unit (60), the guide unit having a curved part
for guiding air such that air around the curved part of the guide unit flows along
the curved part of the guide unit; and
an air flow changing unit (70) disposed between the nozzle unit (60) and the guide
unit such that the air flow changing unit (70) can be rotated along the curved part
of the guide unit for changing flow of air discharged from the nozzle unit (60).
2. The hood as set forth in claim 1, wherein the air flow changing unit (70) comprises:
a louver (72) disposed in the nozzle unit (60) while being spaced a predetermined
distance from the guide unit,
the louver (72) and the guide unit together defining a discharging slit (80) therebetween
such that air is discharged from the nozzle unit (60) through the discharging slit
(80).
3. The hood as set forth in claim 2, wherein the air flow changing unit (70) further
comprises:
a motor (74) for rotating the louver (72).
4. The hood as set forth in claim 3, wherein the louver (72) comprises:
a guide part (82) for guiding flow of air; and
connection parts (84) attached to both ends of the guide part (82), the connection
parts (84) being connected to a rotary shaft of the motor (74).
5. The hood as set forth in claim 4, wherein the guide unit is a ring-shaped rod (62)
mounted to a lower part of the nozzle unit (60).
6. The hood as set forth in claim 5, wherein the ring-shaped rod (62) is formed in a
hollow shape such that the motor (74) is mounted in the ring-shaped rod (62).
7. The hood as set forth in any one of claims 1 to 6, wherein the air flow changing unit
(70) is provided with at least one roller (76) that is in rolling contact with the
curved part of the guide unit.
8. The hood as set forth in claim 7, wherein the at least one roller (76) comprises:
a plurality of rollers attached to the lower surface of the air flow changing unit
(70) while being spaced a predetermined length from each other in the longitudinal
direction thereof.
9. The hood as set forth in claim 8, wherein the rollers (76) are rotatably connected
to the air flow changing unit (70).
10. The hood as set forth in claim 9, wherein the hood body (50) is provided with an auxiliary
inlet port (64), the auxiliary inlet port (64) being disposed above the auxiliary
fan (58) for allowing air to be introduced into the hood body (50) therethrough by
the auxiliary fan (58).