U.S. patent application number 13/204768 was filed with the patent office on 2012-10-25 for duct.
Invention is credited to Shi-Wei Lo, Jr-Ming Miao, Chang-Hsien Tai.
Application Number | 20120270487 13/204768 |
Document ID | / |
Family ID | 47021691 |
Filed Date | 2012-10-25 |
United States Patent
Application |
20120270487 |
Kind Code |
A1 |
Tai; Chang-Hsien ; et
al. |
October 25, 2012 |
Duct
Abstract
A duct including a duct body is disclosed. The duct is a hollow
tube and includes an air channel and an exit end. The exit end has
a windward portion and an air-guiding portion on two sides
thereof.
Inventors: |
Tai; Chang-Hsien; (Neipu
Hsiang, TW) ; Miao; Jr-Ming; (Neipu Hsiang, TW)
; Lo; Shi-Wei; (Neipu Hsiang, TW) |
Family ID: |
47021691 |
Appl. No.: |
13/204768 |
Filed: |
August 8, 2011 |
Current U.S.
Class: |
454/1 |
Current CPC
Class: |
F23L 17/10 20130101;
F24F 7/02 20130101 |
Class at
Publication: |
454/1 |
International
Class: |
E04F 17/04 20060101
E04F017/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2011 |
TW |
100114350 |
Claims
1. A duct comprising a duct body being a hollow tube, wherein the
duct comprises an air channel and an exit end, and the exit end has
a windward portion and an air-guiding portion on two sides
thereof.
2. The duct as claimed in claim 1, wherein the duct body further
comprises a narrow portion.
3. The duct as claimed in claim 1, wherein the duct body further
comprises a first tube and a second tube coupled with the first
tube via a sliding member.
4. The duct as claimed in claim 3, wherein the sliding member is a
ball bearing, a needle bearing, a sliding bearing, a magnetic
suspension bearing, a hydraulic bearing or a tapered and
cylindrical roller bearing.
5. The duct as claimed in claim 3, wherein the first tube further
comprises a pair of wings.
6. The duct as claimed in claim 5, wherein the wings are aligned
with the exit end.
7. The duct as claimed in claim 1, wherein the exit end is formed
as a cut-off portion.
8. The duct as claimed in claim 1, wherein the exit end has an
inclined periphery.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a duct of a
smokestack and, more particularly, to a duct of a smokestack that
provides faster heat expelling by increasing air pressure
difference between interior air and exterior air.
[0003] 2. Description of the Related Art
[0004] Smokestacks are commonly seen in a variety of buildings and
factories. A smokestack has a duct and can create a difference in
air pressure between interior air and exterior air. Heat (or waste
gas) in the duct will rise, and the air pressure difference can
facilitate expelling the heat in the duct while drawing clean air
from the outside at the same time. When the heat gets to an exit of
the smokestack, the wind will blow away the expelled heat, thereby
attaining ventilation and cooling effects of the smokestack.
[0005] Referring to FIG. 1, a conventional duct 9 has an air
channel 91 and an exit 92. The duct 9 can be used to construct a
smokestack for some equipment such as a furnace or the like. The
smokestack has an entry and an exit, and there is a big difference
in air pressure between the entry and the exit. During operation of
the furnace, a significant amount of heat will be generated, and
the heat will rise in the air channel 91 of the duct 9. At this
point, the air pressure difference will push the heat out of the
duct 9. When the rising heat gets to the exit 92 of the duct 9, an
air-pulling effect created by the wind blowing over the smokestack
will blow away the heat. In such a manner, desired ventilation can
be provided to improve burning of the furnace.
[0006] Since the exit 92 of the duct 9 has an even periphery,
however, the wind tends to interact with the expelled heat at the
exit 92. The interaction between the wind and the expelled heat
will slow down the heat in the duct 9. As a result, heat emission
and cooling efficiency of the duct 9 are impacted. In light of this
problem, it is desired to improve the duct 9.
SUMMARY OF THE INVENTION
[0007] It is therefore the primary objective of this invention to
provide a duct capable of increasing the air pressure difference
between interior air and exterior air to better create an
air-pulling effect at an exit of the duct.
[0008] It is another objective of this invention to provide a duct
capable of automatically adjusting the direction thereof based on
wind direction, thus maintaining the air-pulling effect at the exit
of the duct.
[0009] The invention discloses a duct including a duct body. The
duct is a hollow tube and includes an air channel and an exit end.
The exit end has a windward portion and an air-guiding portion on
two sides thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from
the detailed description given hereinafter and the accompanying
drawings which are given by way of illustration only, and thus are
not limitative of the present invention, and wherein:
[0011] FIG. 1 is a cross-sectional view of a conventional duct.
[0012] FIG. 2 is a cross-sectional view of a duct according to a
first embodiment of the invention.
[0013] FIG. 3 is an exploded view of a duct according to a second
embodiment of the invention.
[0014] FIG. 4 is a cross-sectional view of the duct of the second
embodiment of the invention.
[0015] FIG. 5 is a top view of a first tube of the duct rotating
upon a sliding member according to the second embodiment of the
invention.
[0016] FIG. 6 is a top view of the first tube of the duct resting
on the sliding member according to the second embodiment of the
invention.
[0017] FIG. 7 is an exploded view of a duct according to a third
embodiment of the invention.
[0018] In the various figures of the drawings, the same numerals
designate the same or similar parts. Furthermore, when the term
"first", "second", "third", "fourth", "inner", "outer" "top",
"bottom" and similar terms are used hereinafter, it should be
understood that these terms refer only to the structure shown in
the drawings as it would appear to a person viewing the drawings,
and are utilized only to facilitate describing the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIG. 2, a duct including a duct body 1 is
disclosed according to a first embodiment of the invention. The
duct body 1 is a hollow tube and has an air channel 11 that allows
air to pass therethrough. The duct body 1 has an exit end 12 on one
end thereof, and the exit end 12 may form a windward portion 13 and
an air-guiding portion 14. In this embodiment, the exit end 12
forms a cut-off portion with an uneven periphery. Namely, a portion
of circumferential wall of the duct body 1 is cut off at the exit
end 12 to form the cut-off portion. Specifically, the windward
portion 13 has two ends 131 and 132, and the two ends 131 and 132
may jointly define the air-guiding portion 14. The two ends 131 and
132 of the windward portion 13 may be parallel to a vertical
direction of the duct as shown in FIG. 3, but is not limited
thereto.
[0020] Referring to FIG. 2, when the duct is in use, the duct
should be disposed according to wind direction. Specifically, the
windward portion 13 of the duct body 1 should face the wind such
that a high air pressure area A can be defined on a surface of the
windward portion 13. When the strong wind of the high air pressure
area A blows over the cut-off portion of the exit 12, the wind will
be instantaneously speeded up due to the gradient in air pressure,
creating a low air pressure area B on the air-guiding portion 14.
At the instant, the air pressure difference between the high air
pressure area A and the low air pressure area B will result in
boundary layer separation of the airflows on the air-guiding
portion 14. Therefore, eddy occurs. At the same moment, there
results in a difference in air pressure between interior air and
exterior air of the duct body 1, creating an air-pulling effect
that pulls up the air from the air channel 11.
[0021] Referring to FIG. 2, the duct body 1 preferably comprises a
narrow portion 15 which can speed up the heat passing therethrough.
This causes a local low air pressure that facilitates expelling the
heat of the duct body 1 and therefore provides improved air
circulation.
[0022] Referring to FIGS. 3 and 4, a duct is disclosed according to
a second embodiment of the invention. The duct body 1 also has the
exit end 12, windward portion 13, air-guiding portion 14 and narrow
portion 15 described in the first embodiment. The duct of the
second embodiment differs from that of the first embodiment in that
the duct body 1 consists of a first tube 1a and a second tube 1b.
The first tube 1a has a first air channel 11a and the second tube
1b has a second air channel 11b. The exit end 12, windward portion
13, air-guiding portion 14 and narrow portion 15 are formed on one
end of the first tube 1a.
[0023] The first tube 1a and the second tube 1b are coupled
together in various conventional ways. As shown in FIG. 3, the
first tube 1a and the second tube 1b are coupled together via a
sliding member 16. In this embodiment, the first tube 1a further
comprises a first coupling member 17a abutting against one face of
the sliding member 16, with the other face of the sliding member 16
coupled with a coupling seat 17b of the second tube 1b. In such a
manner, the sliding member 16 can support the first tube 1a and
allow the first tube 1a to rotate about the second tube 1b. The
sliding member 16 may be a ball bearing, a needle bearing, a
sliding bearing, a magnetic suspension bearing, a hydraulic
bearing, a tapered and cylindrical roller bearing or any similar
structures that can support the first tube la and provide rotation
therefor. In this embodiment, the sliding member 16 is implemented
as the tapered and cylindrical roller bearing.
[0024] The first tube 1a may further comprise a pair of wings 18
capable of generating a torque when the direction of the wind
changes. The wings 18 are shown to be arranged on the first tube 1a
for illustration purpose. Specifically, the wings 18 are aligned
with each other in a radial direction of the duct while located at
two opposing positions on an outer circumferential face of the
first tube 1a. Further, the wings 18 are preferably located on two
ends of the windward portion 13 and aligned with the cut-off
portion of the exit end 12. Specifically, the wings 18 are aligned
with the cut-off portion in such a way that the wings 18 are
aligned with the two ends 131 and 132 of the windward portion 13 in
the vertical direction. In addition, the wings 18 are preferably
not higher than the cut-off portion of the exit end 12 in order not
to disturb the eddy system at the exit end 12.
[0025] Referring to FIGS. 5 and 6, operation diagrams of the wings
18 and the sliding member 16 are shown. The wings 18 can define a
central reference line X having two ends. The two ends of the
central reference line X may experience different wind strength.
For example, referring to FIG. 5, one end of the central reference
line X may experience larger wind strength than the other one. In
this case, the wings 18 will be driven by the wind and therefore
cause the first tube 1a to rotate via the sliding member 16 until
the two ends of the central reference line X experience the same
wind strength. By the time the first tube 1a stops rotating, the
windward portion 13 of the first tube 1a will face the wind,
allowing eddies to be generated at the exit end 12 of the first
tube 1a. The eddies will help blow away the expelled heat of the
duct. In such an arrangement, the duct in the second embodiment can
automatically adjust the direction of the windward portion 13 based
on wind direction, thereby providing faster heat emission.
[0026] Referring to FIG. 7, a duct is disclosed according to a
third embodiment of the invention. In the third embodiment, the
duct also has the first tube 1a, second tube 1b and narrow portion
15 described above. The duct of the third embodiment differs from
those of the first and second embodiments in that the exit end 12
has an inclined periphery. Similar to the first and second
embodiments, the duct in this embodiment also has the windward
portion 13 and the air-guiding portion 14. Thus, it will be more
convenient to manufacture the first tube 1a.
[0027] The duct of the invention can be installed on a roof of a
building to expel dirty air of the building. Further, the duct of
the invention can also construct a part of a smokestack for a
conventional furnace or the like. In generally, the furnace will
generate a significant amount of heat during the burning process
thereof. Since the heat has a smaller density, the heat will rise
in the duct. At this point, the air-guiding portion 14 can increase
the speed of airflows, creating a low air pressure area B and
resulting in an air pressure difference between interior air and
exterior air of the duct. Thus, the heat at the exit 12 will be
blown away quickly by wind while external clean air is drawn into
the duct via the bottom end of the duct, thereby providing improved
burning of the furnace.
[0028] Although the invention has been described in detail with
reference to its presently preferable embodiment, it will be
understood by one of ordinary skill in the art that various
modifications can be made without departing from the spirit and the
scope of the invention, as set forth in the appended claims.
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