U.S. patent application number 11/568763 was filed with the patent office on 2007-09-27 for kitchen ventilation system with fan having positive pressure-to-output characteristic applied thereto.
Invention is credited to Su-Bin Yi.
Application Number | 20070221198 11/568763 |
Document ID | / |
Family ID | 35320307 |
Filed Date | 2007-09-27 |
United States Patent
Application |
20070221198 |
Kind Code |
A1 |
Yi; Su-Bin |
September 27, 2007 |
Kitchen Ventilation System With Fan Having Positive
Pressure-To-Output Characteristic Applied Thereto
Abstract
The present invention relates to a kitchen ventilation system to
which a fan having a positive pressure-to-output characteristic is
applied. More particularly, the present invention relates to a
system for maximizing efficiency of exhausting polluted air at
minimum costs by applying a fan having a positive
pressure-to-output characteristic to a hood, to improve a
ventilation system which is installed vertically in an apartment
house to discharge polluted air from kitchen hoods on respective
floors to the top of an exhaust duct. The kitchen ventilation
system of the present invention comprises an exhaust duct 100
provided at one side of an apartment house, and a hood 200 which is
provided in the kitchen on each floor and includes a fan 210 having
a positive pressure-to-output characteristic to collect surrounding
air and discharge the collected air to the exhaust duct 100.
According to the present invention, noise can be reduced and
economical efficiency and ventilation performance can also be
improved by maximizing efficiency of exhausting polluted air at
minimum costs.
Inventors: |
Yi; Su-Bin; (Seoul,
KR) |
Correspondence
Address: |
IPLA P.A.
3580 WILSHIRE BLVD.
17TH FLOOR
LOS ANGELES
CA
90010
US
|
Family ID: |
35320307 |
Appl. No.: |
11/568763 |
Filed: |
May 6, 2005 |
PCT Filed: |
May 6, 2005 |
PCT NO: |
PCT/KR05/01328 |
371 Date: |
November 6, 2006 |
Current U.S.
Class: |
126/299R |
Current CPC
Class: |
F24C 15/2021
20130101 |
Class at
Publication: |
126/299.00R |
International
Class: |
F24C 15/20 20060101
F24C015/20 |
Foreign Application Data
Date |
Code |
Application Number |
May 6, 2004 |
KR |
10-2004-0031948 |
Claims
1. A kitchen ventilation system, comprising: an exhaust duct
vertically provided at one side of an apartment house; and a hood
for collecting surrounding air and discharging the collected air to
the exhaust duct, said hood being provided in a kitchen on each
floor of the apartment house and including a fan having a positive
pressure-to-output characteristic.
2. The kitchen ventilation system as claimed in claim 1, wherein
the fan, which is provided in the hood and has a positive
pressure-to-output characteristic, is driven by a fan driving
circuit which includes a 3-phase induction motor for driving the
fan, a power unit for applying electric power to the 3-phase
induction motor, a capacitor C2 connected with the 3-phase
induction motor for producing a phase difference between two
phases, and an impedance unit connected in series with the 3-phase
induction motor for producing a constant amount of air discharged
even though load applied to the fan is changed.
3. The kitchen ventilation system as claimed in claim 2, wherein
the impedance unit includes a capacitor C1, and a resistor R1
connected in parallel with the capacitor C1.
4. The kitchen ventilation system as claimed in claim 2, wherein
the fan driving circuit further comprises a resistor R2 connected
in series with the impedance unit and a switch installed in
parallel with the resistor R2, thereby interrupting a current
flowing along the resistor R2.
Description
TECHNICAL FIELD
[0001] The present invention relates to a kitchen ventilation
system to which a fan having a positive pressure-to-output
characteristic is applied. More particularly, the present invention
relates to a system for maximizing efficiency of exhausting
polluted air at minimum costs by applying a fan having a positive
pressure-to-output characteristic to a hood, to improve a
ventilation system which is installed vertically in an apartment
house to discharge polluted air from kitchen hoods in respective
floors to the top of an exhaust duct, thereby reducing noise and
improving economical efficiency and ventilation performance.
BACKGROUND ART
[0002] In general, a major source of polluting room air in an
apartment house is a variety of harmful materials such as heat,
smell and oil vapor, which are produced when a person cooks in the
kitchen. To discharge the harmful materials produced in the kitchen
to the outside, a hood is installed in the kitchen, and an exhaust
duct is also vertically formed on a side of the building to
communicate with the kitchen hood.
[0003] FIG. 1 is a side sectional view of a conventional kitchen
ventilation system.
[0004] As shown in FIG. 1, the conventional kitchen ventilation
system comprises an exhaust duct 10 which is provided at one side
of an apartment house and includes an exhaust fan 11 formed at an
upper end thereof, a plurality of hoods 20 each of which is
provided in the kitchen on each floor and includes a fan 21 to
collect surrounding air and discharge the collected air to the
exhaust duct 10, and a plurality of pressure sensors 30 which are
provided in the exhaust duct 10 at regular vertical intervals.
[0005] As shown in FIG. 1, the conventional kitchen ventilation
system so configured allows the harmful and polluted materials,
which are produced when a person cooks in the kitchen, to be
collected in and discharged to the outside through the exhaust duct
10 vertically formed on one side of the building, by means of the
hood 20 mounted with the fan 21 which is installed over a
countertop in the kitchen.
[0006] At this time, the fan 21 mounted to the hood 20 allows the
polluted materials in the kitchen to be collected and discharged to
the exhaust duct 10, and the exhaust fan 11 allows the polluted
materials in the exhaust duct 10 to be discharged to the outside of
the building.
[0007] In general, in order to allow the fans 21 of the hoods 20 to
smoothly discharge the polluted materials in the kitchen to the
outside in a high-rise building of 40 to 50 floors, the fans should
exhibit output of power gradually increasing as installation
positions are changed from lower floors to higher floors.
[0008] However, when the hoods 20 with the same output of power as
each other are installed on the lower and higher floors, the output
of power of the fan 21 in the hood 20 installed on the lower floors
is unnecessarily large to discharge the polluted materials in the
kitchen, whereas that installed on the higher floors is
insufficient to discharge the polluted materials. Furthermore,
there is a problem in that the fan 21 in the hood 20 installed in
the kitchen on the higher floors cannot smoothly discharge the
polluted materials due to loss of static pressure as well as the
noise is too greatly increased.
[0009] That is, as load pressure applied to a discharge port of the
fan 21 in the hood 20 installed in the kitchen on the higher floors
is increased, load applied to the fan 21 is also increased.
Therefore, the amount of air discharged is decreased, and thus, the
amount of polluted materials discharged is also decreased.
[0010] To solve the above problem, the plurality of pressure
sensors 30 are additionally installed in the exhaust duct 10 at
regular vertical intervals to independently control the output of
power of the fans 21 in the hoods 20 according to the pressure
detected from the pressure sensors 30.
[0011] In case of the conventional kitchen ventilation system in
which the plurality of pressure sensors measure air pressure in the
exhaust duct at the respective levels to control the output of
power of the fan according to the levels, however, there is a
technical problem in that total manufacturing costs of the
conventional kitchen ventilation system are inevitably high due to
the plurality of pressure sensors for measuring the air pressure
and a microprocessor for processing signals from the pressure
sensors to control the fans.
DISCLOSURE OF INVENTION
[0012] The present invention is conceived to solve the
aforementioned problem in the prior art. An object of the present
invention is to provide a kitchen ventilation system to which a fan
having a positive pressure-to-output characteristic is applied,
wherein the fan having a positive pressure-to-output characteristic
is employed in a kitchen hood on each floor of an apartment house
in which a common exhaust duct is used in both lower and higher
floors of the apartment house such that polluted air in the kitchen
can be effectively discharged without expensive control devices
such as a microprocessor or pressure sensors even though different
loads are applied to the lower and higher floors, whereby its noise
can be reduced and its economical efficiency and ventilation
performance can also be improved by maximizing the efficiency of
exhausting polluted air at minimum costs.
[0013] To achieve the object of the present invention, the kitchen
ventilation system comprises an exhaust duct vertically provided at
one side of an apartment house, and a hood for collecting
surrounding air and discharging the collected air to the exhaust
duct, said hood being provided in a kitchen on each floor of the
apartment hours and including a fan having a positive
pressure-to-output characteristic.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a side sectional view of a conventional kitchen
ventilation system.
[0015] FIG. 2 is a side sectional view of a kitchen ventilation
system to which a fan having a positive pressure-to-output
characteristic is applied according to the present invention.
[0016] FIG. 3 is a circuit diagram of a fan driving circuit
exhibiting a positive pressure-to-output characteristic for use in
the kitchen ventilation system to which the fan having a positive
pressure-to-output characteristic is applied according to an
embodiment of the present invention.
[0017] FIG. 4 is a graph illustrating load curves and operating
points of the fan driving circuit for use in a kitchen ventilation
system to which a fan having a positive pressure-to-output
characteristic is applied according to an embodiment of the present
invention.
[0018] FIG. 5 is a circuit diagram of a fan driving circuit for use
in a kitchen ventilation system to which a fan having a positive
pressure-to-output characteristic is applied according to another
embodiment of the present invention.
[0019] FIG. 6 is a graph illustrating a level/output curve a fan
having a positive pressure-to-output characteristic, which is
installed at each floor and used in a kitchen ventilation
system.
BEST MODE FOR CARRYING OUT THE INVENTION
[0020] Hereinafter, a preferred embodiment of the present invention
will be described in detail with reference to the accompanying
drawings.
[0021] FIG. 2 is a side sectional view of a kitchen ventilation
system to which a fan having a positive pressure-to-output
characteristic according to the present invention is applied, and
FIG. 3 is a circuit diagram of a fan driving circuit for use in a
kitchen ventilation system to which a fan having a positive
pressure-to-output characteristic is applied according to an
embodiment of the present invention.
[0022] FIG. 4 is a graph illustrating load curves and operating
points of the fan driving circuit for use in a kitchen ventilation
system to which a fan having a positive pressure-to-output
characteristic is applied according to an embodiment of the present
invention, FIG. 5 is a circuit diagram of a fan driving circuit for
use in a kitchen ventilation system to which a fan having a
positive pressure-to-output characteristic is applied according to
another embodiment of the present invention, and FIG. 6 is a graph
illustrating a level/output curve a fan having a positive
pressure-to-output characteristic, which is installed at each floor
and used in a kitchen ventilation system.
[0023] As shown in FIG. 2, a kitchen ventilation system to which a
fan having a positive pressure-to-output characteristic is applied
comprises an exhaust duct 100 provided at one side of an apartment
house, and a hood 200 which is provided in the kitchen on each
floor and includes a fan 210 to collect surrounding air and
discharge the collected air to the exhaust duct 100.
[0024] Hereinafter, the operation of the present invention will be
explained with reference to FIGS. 2 to 6.
[0025] As shown in FIGS. 2 and 3, the kitchen ventilation system,
to which the fan having a positive pressure-to-output
characteristic is applied, of the present invention so configured
allows the polluted materials, which are produced when a person
cooks in the kitchen, to be collected in and discharged to the
outside through the exhaust duct 100 vertically formed on one side
of the building, by means of the hood 200 mounted with the fan 210
which is installed over a countertop in the kitchen. In addition,
the fan 210 provided in the hood 200 allows the polluted materials
in the kitchen to be collected and discharged to the outside
through the exhaust duct 100.
[0026] A back draft damper is installed between the hood 200 and
exhaust duct 100 shown in FIG. 2 such that the polluted materials
remaining in the exhaust duct 100 can be prevented from flowing
back into the room through the hood 200 when the fan 210 of the
hood 200 is not in use.
[0027] At this time, in order to allow the fans 210 of the hood 200
to smoothly discharge the polluted materials in the kitchen to the
outside in a high-rise building of 40 to 50 floors, the fans 210
should exhibit output of power gradually increasing as their
installation positions are changed from lower floors to higher
floors, as shown in FIG. 6.
[0028] To this end, it is preferable to provide the fan 210 having
a positive pressure-to-output characteristic in each of the hoods
200 installed in the kitchen on each floor of the building. In such
a case, the fan 210 having a positive pressure-to-output
characteristic is installed in the hood 200 such that the hood
installed in high-rise building can exhibit adequate output of
power regardless of its installation level. Therefore, the polluted
materials in the kitchen can be effectively discharged to the
outside of the building, i.e. to the outside of the exhaust duct
100, without any additional exhaust fan.
[0029] The aforementioned fan 210 having a positive
pressure-to-output characteristic is preferably controlled by means
of a fan driving circuit in which additional microprocessor and
pressure sensors are not included. Preferably, the fan 210, which
is provided in the hood 200 and has a positive pressure-to-output
characteristic, is driven by the fan driving circuit. As shown in
FIG. 3, the fan driving circuit of the present invention comprises
a 3-phase induction motor 310 for driving the fan 210, a power unit
320 for applying electric power to the 3-phase induction motor 310,
a capacitor C2 330 which is connected with the 3-phase induction
motor 310 to produce a phase difference between two phases, and an
impedance unit 340 which is connected in series with the 3-phase
induction motor 310 to produce a constant amount of air discharged
even though load applied to the fan 210 is changed.
[0030] Preferably, the impedance unit 340 includes capacitor C1 341
and a resistor Ri 342 connected in parallel with the capacitor C1
341.
[0031] As shown in FIG. 4, therefore, in cases where lower and
higher voltages (respectively refer to curve A and curve B) are
applied to the 3-phase induction motor 310 (refer to FIG. 3)
according to the load applied to the fan 210, operating points A'
and B', which are operating on lower and higher voltages, are shown
along a load curve C, respectively.
[0032] That is, to create a positive pressure-to-output
characteristic curve of the kitchen ventilation system mounted with
the fan 210 serving as a load of the 3-phase induction motor 310,
the impedance unit 340, which includes the capacitor C1 341 and the
resistor R1 342 as a serial load, is added to a conventional
driving circuit for the 3-phase induction motor 310 including a
capacitor. Therefore, an alternating voltage with constant
amplitude is applied to the 3-phase induction motor 310 due to
voltage distribution of an alternating voltage with constant
amplitude and frequency between the 3-phase induction motor 310
including the capacitor C2 330 and the impedance unit 340 serving
as load in series therewith.
[0033] At this time, the fan driving circuit operates at
equilibrium points for the torque and rotating speed relationship
due to the positive pressure-to-output characteristic curve shown
in FIG. 4. In FIG. 4, a curve C is a load curve of the fan 210, a
curve A is an output characteristic curve of the 3-phase induction
motor 310 when the lower voltage is applied thereto, and a curve B
is an output characteristic curve of the motor when the higher
voltage is applied thereto.
[0034] The operating principle will be discussed in detail with
reference to FIGS. 3 and 4. If the load applied to the fan is
increased while the 3-phase induction motor 310 is rotating at a
constant frequency at an operating point A', slip in the 3-phase
induction motor 310 is increased. Accordingly, equivalent impedance
of the 3-phase induction motor 310 is reduced, and thus, the
current is increased.
[0035] At this time, the rotating speed of the motor is rapidly
increased due to generated torque proportional to the square of
current, and thus, the equivalent impedance of the 3-phase
induction motor is again increased. Therefore, the voltage
distributed to the constant serial load is also increased (refer to
curve B), and the motor is rotated at a new operating point B'.
[0036] That is, under the load characteristic of the fan 210 having
a positive pressure-to-output characteristic as shown in FIG. 4, an
applied voltage is increased as the load is increased. Thus, the
motor is in a stable state at the operating point where the
rotating speed of the motor is higher.
[0037] On the contrary, if the load in the fan is decreased, the
equivalent resistance is instantly increased and the current is
simultaneously decreased. Thus, the rotating speed of the motor is
rapidly reduced and the equivalent impedance is also reduced, and
the lower voltage is consequently applied to the 3-phase induction
motor 310 (refer to a curve A). Accordingly, the motor stably
operates at a new operating point A'.
[0038] That is, the load applied to the fan is continuously
changed, and the operating points can also be maintained between
the maximum and minimum speed-to-torque operating points that the
3-phase induction motor 310 can operate.
[0039] As shown in FIG. 5, a fan driving circuit for use in a
kitchen ventilation system to which a fan having a positive
pressure-to-output characteristic is applied according to another
embodiment of the present invention further comprises a resistor R2
350 connected in series with the impedance unit 340 and a switch
360 connected in parallel with the resistor R2 350. Accordingly,
the switch 360 can interrupt the current flowing in the resistor R2
350.
[0040] That is, as shown in FIG. 5, if the switch 360 and resistor
R2 350 connected in parallel with each other are added to the fan
driving circuit, resistance in the serial load is increased and the
3-phase induction motor 310 is kept at a lower rotating speed. At
this time, if the switch 360 is turned on to cut off the current
flowing in the resistor R2 350, the voltage distributed to the
3-phase induction motor 310 is rapidly increased and thus the
rotating speed of the fan 210 may be rapidly increased.
INDUSTRIAL APPLICABILITY
[0041] According to the kitchen ventilation system of the present
invention to which a fan having a positive pressure-to-output
characteristic is applied, since the fan 210 controlled by the
positive pressure-to-output characteristic fan driving circuit is
installed in the hood 200 provided in the kitchen of the high-rise
building, the fan having a positive pressure-to-output
characteristic can perform an active control of the output of power
in accordance with a level where the hood 200 is installed.
Therefore, there is an advantage in that polluted materials in the
kitchens on the respective floors can be easily discharged through
the exhaust duct 100 to the outside, because the fan 210 is
rotating faster as the installation level is changed from lower
floors to higher floors.
[0042] Therefore, a fan having a positive pressure-to-output
characteristic is employed in the kitchen hood on each floor of an
apartment house in which a common exhaust duct is used in both
lower and higher floors of the apartment house such that polluted
air in the kitchen can be effectively discharged without expensive
control devices such as a microprocessor or pressure sensors even
though different loads are applied to the lower and higher floors,
whereby noise can be reduced and economical efficiency and
ventilation performance can also be improved by maximizing the
efficiency of exhausting polluted air at minimum costs.
* * * * *