U.S. patent application number 15/272475 was filed with the patent office on 2017-01-12 for high efficiency fluid delivery system.
This patent application is currently assigned to TurboChef Technologies, Inc.. The applicant listed for this patent is TurboChef Technologies, Inc.. Invention is credited to Carl J. Dougherty.
Application Number | 20170010003 15/272475 |
Document ID | / |
Family ID | 36740844 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170010003 |
Kind Code |
A1 |
Dougherty; Carl J. |
January 12, 2017 |
HIGH EFFICIENCY FLUID DELIVERY SYSTEM
Abstract
A high efficiency fluid delivery system which is particularly
useful in delivering temperature-controlled air in convection
heating or cooling apparatuses is described. The fluid delivery
system preferably comprises fluid circulation means having an
intake opening for the fluid and vanes that assist in increasing
fluid velocity and reducing turbulent flow.
Inventors: |
Dougherty; Carl J.;
(Carrollton, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TurboChef Technologies, Inc. |
Atlanta |
GA |
US |
|
|
Assignee: |
TurboChef Technologies,
Inc.
Atlanta
GA
|
Family ID: |
36740844 |
Appl. No.: |
15/272475 |
Filed: |
September 22, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11794525 |
Jul 15, 2008 |
9474284 |
|
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PCT/US2006/002335 |
Jan 25, 2006 |
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15272475 |
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60647253 |
Jan 26, 2005 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A21B 1/245 20130101;
Y10T 137/86131 20150401; A21B 1/48 20130101; Y10T 137/85986
20150401; F24C 15/322 20130101; Y10T 137/0318 20150401 |
International
Class: |
F24C 15/32 20060101
F24C015/32 |
Claims
1. A fluid delivery system, comprising: a first fluid circulation
member comprising an intake opening for fluid; and at least one
vane mounted adjacent the intake opening, wherein the at least one
vane is disposed in a substantially radial position relative to a
center point of the intake opening.
2. The system of claim 1, wherein the vane is disposed in a
substantially horizontal position.
3. The system of claim 1, wherein said fluid is a gas or air.
4. The system of claim 1, wherein the first fluid circulation
member comprises a first blower having a first blower wheel for
circulating temperature controlled gas within the system, the first
blower wheel comprising the intake opening; a second blower having
a second blower wheel for circulating temperature controlled gas
within the system, the second blower wheel comprising a second
intake opening; a motor operably connected to and which rotates a
shaft, each of the first blower wheel and the second blower wheel
being connected to the shaft for rotation of the first and second
blower wheels by the shaft; and at least a second vane mounted
adjacent the second intake opening of the second blower wheel.
5. The system of claim 4, wherein each of the vanes is disposed in
a substantially radial position relative to the center point of the
intake opening to which it is adjacent.
6. The system of claim 4, further comprising: a third blower having
a third blower wheel for circulating temperature controlled gas
within the system, the third blower wheel comprising a third intake
opening, the third blower wheel being connected to the shaft for
rotation of the third blower wheel by said shaft.
7. A gas delivery system for a heating or cooling apparatus
comprising: a first blower having a first blower wheel for
circulating temperature controlled gas within the apparatus, the
blower wheel comprising an intake opening; a second blower having a
second blower wheel for circulating temperature controlled gas
within the apparatus, the second blower wheel comprising a second
intake opening; a third blower having a third blower wheel for
circulating temperature controlled gas within the apparatus, the
third blower wheel comprising a third intake opening; a motor
operably connected to and which rotates a shaft, each of the first
blower wheel, the second blower wheel, and the third blower wheel
being connected to said shaft for rotation of the blower wheels by
the shaft; a first vane mounted adjacent said intake opening of the
first blower wheel and the second intake opening of the second
blower wheel; and a second vane mounted adjacent the second intake
opening of the second blower wheel and the third intake opening of
the third blower wheel.
8. The apparatus of claim 7, wherein each vane is disposed in a
substantially radial position with respect to the center point of
the intake opening to which it is adjacent.
9. The apparatus of claim 7, wherein each vane is disposed in a
substantially horizontal position.
10. A method of delivering fluid, comprising: providing the
apparatus of claim 1; and reducing turbulence of fluid entering the
system adjacent the intake opening via contact of the fluid with
the at least one vane.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. Nonprovisional
patent application Ser. No. 11/794,525 filed on Jun. 28, 2007,
which application is the U.S. national phase entry of International
Application No. PCT/US2006/002335 filed on Jan. 25, 2006, which
application claims priority to U.S. Provisional Patent Application
No. 60/647,253 filed on Jan. 26, 2005, the contents the each of
which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a high efficiency fluid
delivery system which is particularly useful in delivering
temperature-controlled air in convection heating or cooling
apparatuses.
BACKGROUND
[0003] The movement of fluids is used in numerous devices and
applications to achieve desired results. For example, convection
and impingement ovens move heated air or gas into a cooking chamber
to enhance the rate of cooking. Impingement freezers move cold air
or gas into a freezing chamber to enhance the rate of product
freezing. Personal watercraft move water (e.g., water jets) for
propulsion. Heater and air conditioners move temperature controlled
air. But with many devices, including those listed above, there is
a continual demand to achieve higher performance without increasing
the size or footprint of the device. Higher performance in devices
that operate by fluid movement often times requires higher fluid
flow rates. However, significant engineering problems arise when
attempting to achieve such higher flow rates within devices that
have limited space to handle the fluid flow. Such problems arise
when attempting to "turn" the flow of fluid within confined spaces,
as fluid turbulence (e.g., rotational turbulence) is created and
reduces the efficiency of the circulation means (e.g., a
blower).
[0004] One area where such problems have been encountered is with
impingement ovens. While various conveyorized impingement oven
designs are known and available for commercial food service
applications, there continues to be demand for higher performance,
cost-effective ovens. One approach manufacturers have taken to
improve air flow into the cooking cavity is to use multiple
blowers. But when one blower is positioned closely to another, or
if a blower is positioned in a confined space, air flow (and hence
cooking efficiency) is negatively affected due to turbulence,
particularly rotational turbulence.
[0005] The present invention provides a design for a fluid delivery
system that significantly reduces the negative affects of
turbulence encountered when fluids are forced to flow and turn in a
confined area. In the present application, the fluid delivery
system is described in the environment of a conveyor-impingement
oven having multiple blower wheels in close proximity to each
other, an environment that creates significant rotational
turbulence adjacent the blower intakes. However, the solution to
reducing turbulence that negatively impacts the efficiency of a
fluid blower means described herein is not limited to impingement
or convection ovens, but has application to any fluid delivery
system.
SUMMARY
[0006] According to certain embodiments of the invention, a fluid
delivery system comprises a first fluid circulation means having an
intake opening for the fluid and at least one vane mounted adjacent
to the intake opening. The vane may be disposed in a substantially
radial position relative to the center point of the intake opening.
The vane may also be disposed in a substantially horizontal
position.
[0007] According to certain embodiments of the invention, a fluid
delivery apparatus comprises first and second blowers, each having
lower wheels for circulating temperature-controlled gas within the
apparatus and the blower wheels having an intake opening. A motor
is preferably connected to, and rotates the shaft of each of the
blower wheels. At least one vane is preferably mounted adjacent to
the intake openings of each blower wheel. It should be understood
that the apparatus may have additional blower wheels, if
desired.
BRIEF DESCRIPTION
[0008] FIG. 1 is a perspective (transparent) view of a fluid
delivery system according to certain embodiments of the present
invention in a conveyor impingement oven;
[0009] FIG. 2 is a cross-sectional side view of a fluid delivery
system according to certain embodiments of the present invention in
a conveyor impingement oven; and
[0010] FIG. 3 is a top (transparent) view of a gas delivery system
according to certain embodiments of the present invention in a
conveyor impingement oven.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The description of the invention provided below is made with
reference to the drawings attached hereto. The drawings have been
consecutively numbered as FIGS. 1-3.
[0012] In FIGS. 1-3, there is shown a conveyorized impingement
oven. As shown, the oven 10 includes an exterior cabinet 12 defined
by exterior side walls 16 and 18, exterior front wall 20, exterior
rear wall 22, exterior top wall 24, and exterior bottom wall 26
(hereinafter collectively referred to as the "exterior walls 29" of
the cabinet or oven). The configuration of cabinet 12 may vary
depending upon the type of oven installation. Generally, cabinet 12
will comprise rectangular-shaped exterior walls and be of a box
shape. Particularly suitable materials for the exterior walls
include aluminized steel and stainless steel. An entrance opening
74 and exit opening 76 are provided in the exterior side walls
through which food products may enter and exit the cooking cavity
28.
[0013] In the preferred embodiment of the invention, food products
are transported into and through cooking chamber 28 by a conveyor
(not shown). Conveyor assemblies of conventional design (e.g., see
U.S. Pat. No. 4,338,911 and U.S. Pat. No. 4,462,383, hereby
incorporated by reference) are suitable. Preferably, the conveyor
assembly comprises a continuous loop wire mesh conveyor belt which
extends through entrance opening 74 and exit opening 76 in the oven
and is horizontally disposed as it travels through cooking chamber
28. A conventional Flat-Flex.RTM. stainless steel wire mesh belt is
suitable, although other types of belts and materials may be used
if desired. The width of the belt is a matter of choice, but belt
widths of about 9-32 inches are typical. The conveyor belt can be
driven by a conventional variable speed electric motor. FIGS. 1-3
show rods 80, which provide support for the conveyor belt.
Preferably, the conveyor belt extends a sufficient distance from
the exit and entrance openings in the oven to allow food products
to be readily positioned on the conveyor belt for travel through
the cooking chamber of the oven and removal upon exiting the oven.
With respect to the conveyance of food product through the oven, it
is desirable to incorporate a programmable conveyor speed
controller to control cook time. Such controllers are well known in
the field of conveyorized impingement ovens. Such controllers, for
example, can be calibrated to control the time the food product is
to be heated in the oven. Disposed within cooking chamber 28 are
upper air dispensing ducts 100a and 100b positioned above the
conveyor belt and a lower air dispensing duct 102 disposed below
conveyor belt. These ducts can be constructed of any of several
known materials capable of withstanding and performing under the
high temperature conditions of the oven, such as, for example,
aluminized steels and stainless steels. Ducts 100a, 1006 and 102
are hollow and arranged to direct jets of heated air against the
surface of food product on the conveyor belt. As shown, the ducts
are preferably tapered along their respective longitudinal axes,
with the cross sectional area (perpendicular to longitudinal axes)
of the ducts being greater at their proximal ends (104a, 104b,
104c) and smaller at their respective distal ends 106a, 106b and
106c. Each of the hollow ducts 100a, 100b and 102 have a perforated
surface or jet plate 110 facing the conveyor belt in which orifices
or openings 112 are formed. Openings 112 are designed to direct
streams of heated air against a food product being transported on
the conveyor belt. In a preferred embodiment, the openings 112
comprise circular nozzles.
[0014] The size and arrangement of the ducts 100a, 100b and 102 may
vary depending on the size of the oven and the desired results.
According to certain embodiments, the conveyor width is about 20
inches, the length of the cooking cavity is about 18-22 inches
(from interior side wall to side wall), and the vertical distance
between the upper duct jet plates and the lower duct jet plate is
about 4 inches, which provides about 3 inches between the upper
ducts (100a and 100b) and the conveyor belt.
[0015] In certain embodiments of the present invention, the ducts
100a, 100b and 102 have a dual taper configuration. As best shown
in FIG. 2, the dual tapered ducts preferably have a first tapered
portion 122 (adjacent their respective proximal ends of the duct)
and a second tapered portion 124 (adjacent their respective distal
ends of the duct). As shown, the first tapered portion 122
preferably has a greater angle of taper than the second tapered
portion 124 which has a gentler slope. The first tapered portion
122 extends approximately one-third the length of the duct. The
degree of taper in the first and second tapered portions may vary.
Preferably, the first tapered portion 122 tapers down such that the
cross-sectional area of the duct is reduced by one half (i.e., the
cross-sectional area at the far end of the first tapered portion is
approximately one-half of the cross-sectional area of the proximal
end of the duct). The second tapered portion 124 preferably tapers
down to about 1/2 inch in height at the distal end of the duct.
This dual taper duct configuration has been found to provide
improved evenness of air flow from the openings along the length of
the ducts and thus improves evenness of cooking.
[0016] Referring to FIG. 3, a plate 308 is disposed between upper
ducts 100a and 100b. As shown, the plate is disposed adjacent the
proximal ends of the upper ducts and can be described as having a
substantially symmetrical "U" or "V" shaped cut-out on the side
furthest from the blowers. The purpose of plate 308 is to control
the path of air returning to the blowers through opening 306. As
shown in FIG. 3, plate 308, with its "U" or "V" shaped cut-out,
forces the air from the cooking cavity to exit the cooking cavity
at approximately the midpoint between the upper ducts. This serves
to balance the air return, minimizing the egress of cooking air out
of the oven and the ingress of room air into the oven through the
conveyor exit and entrance openings.
[0017] As best shown in FIGS. 1 and 3, heated air is circulated
within the oven by blower wheels 300, 302 and 304, respectively.
Each of the blower wheels is mounted on a common shaft 332, which
is driven by a motor (not shown). According to certain embodiments,
the shaft 332 has a diameter of about 3/4 inches. Although not
shown in the figures, the motor that drives the blower shaft 332
can be mounted in any practical position, such as on a bracket
below the shaft. Blower wheels 300, 302 and 304 draw heated air
from the cooking cavity 28 (through return opening 306) and
circulates that air into the ducts 100a, 100b and 102,
respectively. Although the fluid (air) circulation means described
above is a blower wheel type, other well-known fluid circulation
means can be used.
[0018] As shown in the figures and described above, the return air
flow path is restricted to a confined area requiring the return air
to turn at about a 90 degree angle into the blower intake openings
in a relatively short distance. When fluids are forced to turn at
such severe angles in close proximity to the blower intake,
turbulence is created, drastically reducing the ability of the
blower to produce desired high flow rates. Exacerbating the
turbulence in the impingement oven embodiment described above is
the close proximity of the blower intakes to each other. It has
been discovered, however, that such turbulence and its negative
impact on flow rates can be reduced. Disposed at the intake
openings of the blowers are vanes 310 and 312. As shown, vanes 310
and 312 span across the intake opening of the blowers and are
disposed in a substantially radial position with respect to the
center point of their adjacent blower intake openings. According to
certain embodiments as depicted in FIGS. 1-3, vanes 310 and 312 are
arranged in a substantially horizontal position. The vanes can be
mounted to the blower housings by welding or any other suitable
means, such as by brackets and screws. Also, as shown in FIGS. 1
and 2, vanes 310 and 312 each have in their respective center
regions a u-shaped section 314 corresponding to the shape of shaft
332, which allows the vanes to be better centered across the blower
intake openings. The width and thickness of the vanes may vary. In
the arrangement shown in FIGS. 1-3, the width of each vane is
approximately equal to the distance between the blower housings,
the length spans the respective blower intake opening, and the
thickness of each vane is about 1/16 of an inch 1/16 ''). It has
been found that a substantially horizontal vane arrangement
produces the best results for the blower and return air flow
arrangement depicted in FIGS. 1-3 and substantially increases the
velocity of air through the ducts when compared with the blower
arrangement without the vanes. It is theorized that vanes decrease
the rotational turbulence of the air entering the blower intakes,
thereby improving air intake and blower efficiency. While it has
been observed that the horizontal arrangement of the vanes yields
optimum results, the vanes can be tilted from the horizontal and
yield improved velocities over the same oven without the vanes.
[0019] Another advantage of the vane (310, 312) design depicted
herein is that they cover only a small fraction of the area of the
blower intake opening. Consequently, the vanes do not substantially
restrict the flow of fluid into the blower intakes and do not cause
a substantial loss of fluid pressure.
[0020] Preferably, the blower motor used to rotate the blower
wheels should be capable of blower wheel speeds of 3450 rpm. A 1/2
horsepower motor is typically suitable. In certain embodiments,
blower wheels 300, 302 and 304 are forward-inclined type wheels
having a diameter of about 43/4 inches. Also, according to certain
embodiments and as depicted in the figures, the width of blower
wheels 300 and 302 is about 21/2 inches and blower wheel 304 is a
double wheel (two 3 inch wheels) having a total width of about 6
inches. In this configuration, blower wheel 304 is designed to
intake air on both the left side and right side, blower wheel 300
intakes air on its left side (see FIG. 3, arrow indicating air flow
into blower 300) and blower 302 intakes air on its right side (see
FIG. 3, arrow indicating air flow into blower 302). It has been
found that the blower arrangement described above produces air
velocities from the jet plates of about 4700 fpm (feet per minute)
and heat transfer rates of about 26 to 27 BTU/(hr.)(sq.
ft.)(.degree. F.) (heat transfer rates as measured by a heat
transfer measurement device of the type disclosed in U.S. Pat. No.
5,161,889) on the bottom of a food product (conveyor closer to
bottom duct) and about 20 BTU/(hr.)(sq. ft.)(.degree. F.) on the
top side. The same oven without the vanes produced air velocities
of only about 2800 fpm.
[0021] The temperature of the circulated air or gas can be produced
and controlled by any known means. Gas heated and electrically
heated means are the most common. One particularly suitable means
to heat and control the temperature of the air is by well known
electric heating rods (i.e., Calrod.RTM.). According to certain
embodiments, the heating elements are of a dual element heater
design that can be activated separately or simultaneously for power
management. The heating rods can be disposed in any suitable
location and can be of an open coil or sheathed type. According to
certain embodiments, the heating means are disposed down stream of
the cooking cavity return opening and upstream from the blower
intake openings.
[0022] Although embodiments of the present invention have been
described in the context of a conveyor impingement oven, the
concept of reducing fluid turbulence at the intake opening of a
blower or other fluid circulation means is broadly applicable to
other apparatuses which move fluids at high rates. For example, the
vane described herein has application to high velocity (e.g.,
impingement) air freezing devices, impingement batch ovens, air
conditioning and heating devices, water jet propelled watercraft,
and other devices where rotational turbulence is present at the
intake opening(s) of the air circulation means.
[0023] The present invention is not limited to the examples
illustrated above, as it is understood that one ordinarily skilled
in the art would be able to utilize substitutes and equivalents
without departing from the present invention.
* * * * *