U.S. patent application number 11/342138 was filed with the patent office on 2006-06-08 for boilerless steamer apparatus.
Invention is credited to Roger R. JR. Moore, Michael Gibson Parsons.
Application Number | 20060120700 11/342138 |
Document ID | / |
Family ID | 33417844 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060120700 |
Kind Code |
A1 |
Moore; Roger R. JR. ; et
al. |
June 8, 2006 |
Boilerless steamer apparatus
Abstract
A boilerless steamer apparatus is provided having a steamer
cavity formed of a steam generating space and a cooking space,
wherein the steam generating space is separated from the cooking
space by a removable steam lid. The present boilerless steamer
apparatus can provide between 7 to 10 lbs./hour (per pan) of steam.
Various methods to easily clean the boilerless steamer apparatus
are provided.
Inventors: |
Moore; Roger R. JR.;
(Brandon, MS) ; Parsons; Michael Gibson; (Brandon,
MS) |
Correspondence
Address: |
BUTLER, SNOW, O'MARA, STEVENS & CANNADA PLLC
6075 POPLAR AVENUE
SUITE 500
MEMPHIS
TN
38119
US
|
Family ID: |
33417844 |
Appl. No.: |
11/342138 |
Filed: |
January 27, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10439604 |
May 16, 2003 |
7024104 |
|
|
11342138 |
Jan 27, 2006 |
|
|
|
Current U.S.
Class: |
392/386 |
Current CPC
Class: |
A21B 3/04 20130101; A47J
27/16 20130101 |
Class at
Publication: |
392/386 |
International
Class: |
A61L 9/03 20060101
A61L009/03 |
Claims
1. A boilerless steamer apparatus comprising: (a) a steamer cavity
formed by a steamer cavity wall consisting essentially of a steam
generating space separated from a cooking space by a removable
steam lid, wherein said removable steam lid is spaced apart from
said steam cavity wall to form a pressure differential between said
cooking space and said steam generating space; and (b) means to
remove condensate from said cooking space. (c) wherein steam in
said steam generating space is generated by a plurality of gas
burners.
2. The apparatus of claim 1 wherein said steamer cavity is shaped
to accommodate a sufficient number of gas burners to provide
between 48,000-75,000 BTU/hour.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. Ser. No. 10/439,604
filed May 16, 2003
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE TO A "MICROFICHE APPENDIX"
[0003] NOT APPLICABLE
FIELD OF THE INVENTION
[0004] This invention relates to a boilerless steamer apparatus
wherein a steam generator is integral to the steamer cavity and
methods of cleaning.
BACKGROUND OF THE INVENTION
[0005] The steamer is a vital part of many commercial and
institutional kitchens. Since its introduction, the bulk steamer
has been the only steamer appliance capable of producing adequate
steam for rapid and large volume food production. All of these bulk
steamers feature a cavity for cooking food product and a separate
steam generator for steam production connected via steam
transmission tube. The problem with this design of a steam
generation system is the formation of lime scale inside the steam
generator. Many cleaning methods and different generator designs
have been developed over the years; however nothing has been
developed to effectively and efficiently eradicate the lime scale
build up, which results in steamer down-time and costly service
calls. These service calls are required to professionally clean the
steam generator or replace it.
[0006] Bulk steamers with the steam generator separate from the
cavity cannot be thoroughly cleaned by the user of the equipment,
thus creating service calls and unnecessary down time.
Connectionless steamers can be made with a steam generator which is
integral to the steamer cavity. However, these connectionless
steamers do not create the same amount of steam as a bulk steamer.
In a connectionless steamer, the condensate forms and is then
reintroduced to the boiling reservoir. A connectionless steamer
does not have a condensate drain or a water trapping lid. For the
end user that needs the power of the bulk steamer, the
connectionless steamer is not an option, but the need for an easy
to clean generator is still there.
SUMMARY OF THE INVENTION
[0007] Unlike the traditional bulk steamers, the present boilerless
steamer apparatus has a steam generator which is integral to the
steamer cavity thus making the steam generator easily accessible
for operator cleaning. The present boilerless steamer apparatus
features the cooking power of a bulk steamer with the cleaning
benefits of a connectionless steamer.
[0008] The present invention provides a boilerless steamer
apparatus with a steamer cavity formed by a steamer cavity wall
consisting essentially of a steam generating space separated from a
cooking space by a removable steam lid. The removable steam lid is
spaced apart from the steam cavity wall to form a pressure
differential between the cooking space and the steam generating
space. The removable steam lid is formed to remove condensate from
the cooking space.
[0009] The present invention provides an easily cleaned boilerless
steamer apparatus by removing the removable steam lid for cleaning
and replacing the removable steam lid into the apparatus.
[0010] The present invention provides a method for providing an
easily cleanable boilerless steamer apparatus by cleaning the
removable steam lid in place.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a front view of the boilerless steamer apparatus
of the present invention.
[0012] FIG. 2 is a partial side view taken along sectional line 2-2
of the boilerless steamer apparatus of FIG. 1.
[0013] FIG. 3 is a partial side view taken along section line 3-3
of the boilerless steamer apparatus of FIG. 1.
[0014] FIG. 4 is a view of the left side of the boilerless steamer
apparatus of FIG. 1 with the outer cover removed.
[0015] FIG. 5 is a view of the right side of the boilerless steamer
apparatus of FIG. 1 with the outer cover removed.
[0016] FIG. 6 is a partial rear view taken along section 6-6 of
FIG. 5.
[0017] FIG. 7 is an isometric view of the steamer lid which
separates the steam cooking cavity from the steam generating
cavity.
[0018] FIG. 8 is a partial front view taken along section line 8-8
of FIG. 4 showing steam and vent flow paths.
[0019] FIG. 9 is a view of the left side of FIG. 4 showing steam
and vent flow paths.
[0020] FIG. 10 is a front view of an isolated steam chamber of an
alternative embodiment substituting gas burners for electric
resistance heating element.
[0021] FIG. 11 is a partial side view taken along section line
11-11 of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
[0022] This invention relates to a boilerless steamer apparatus
that produces steam at a rate similar to a bulk steamer. A bulk
steamer is defined as a steamer that requires a drain connection,
power connection (gas or electric) and water connection for
steaming and condensate. Some connectionless type steamers have
options for water fill and drain but are not necessary for the
operation of the unit. The present invention produces between 7 to
10 lbs./hour per pan of steam.
[0023] FIG. 1 shows a boilerless steamer apparatus 1 of the present
invention. Boilerless steamer apparatus 1 has a door 2 located at
the front of the boilerless steamer apparatus 1.
[0024] FIG. 2 shows the inside view of the right side of the
interior of the entire boilerless steamer apparatus 1. Door 2 is on
the front of the cooking space 10. A plurality of racks 3 supports
food pans, not shown, at different heights. The present invention
contemplates between 3 to 10 food pans of standard height and
length. Fan 4 is adjacent to sidewall and draws the steam across
the food pans. The fan 4 is in the steamer cavity walls 39 opposite
the inlet ports of the plurality of steam routing paths 23. The
steamer cavity 40 is formed by steamer cavity walls 39. The steamer
cavity 40 is made of a cooking space 10 and a steam generating
space 11. The cooking space 10 is separated from steam generating
space 11 by a removable steam lid 6. The steam generating space 11
includes means to generate steam and thus provide steam to
boilerless steamer apparatus 1. The means to generate steam in the
steam generating space 11 include a plurality of heating elements 9
or gas burners 41. The steam generating space 11 delivers between 7
to 10 lbs./hour/pan to the cooking space 10.
[0025] Removable steam lid 6 separates cooking space 10 above it
from steam generating space 11 below it. The removable steam lid 6
can be made of stainless steel, such as 304 stainless steel or an
NSF approved equivalent. The boilerless steamer apparatus 1 has
integrated the means to generate steam into the steamer cavity 40.
This design allows the operator easy access to the steam generating
space 11 for cleaning lime scale and other contaminants from the
heated surface 45. Access to the steam generating space 11 is
provided via a removable steam lid 6.
[0026] Removable steam lid 6 has several functions. First, the
removable steam lid 6 separates the cooking space 10 from the steam
generating space 11. The removable steam lid 6 makes the boilerless
steamer apparatus 1 much safer to operate by keeping the rapidly
boiling water and the heated surface 45 of steam generating space
11 from being accidentally contacted by an operator.
[0027] Second, the space between the removable steam lid 6 and the
steamer cavity walls 39 are minimized. This design allows the steam
generating space 11 below the removable steam lid 6 to operate at a
slightly higher pressure than the cooking space 10. This pressure
differential is vital to general direction of steam flow. The
higher pressure in the steam generating space 11 forces steam
through a plurality of substantially vertical tube steam delivery
path 23 and into the cooking space 10. Also, this dividing function
minimizes the boil quench affect when cold or frozen food product
is placed in the boilerless steamer apparatus 1. The cold
environment of the food product does not reduce the steam
production rate in the steam generating space 11.
[0028] Third, in the preferred embodiment, the steam routing from
the steam generating space 11 is external of the steamer cavity 40
via the aforementioned plurality of substantially vertical tube
steam delivery path 23. Routing these substantially vertical tube
steam delivery paths 23 external of the steamer cavity 40 helps
establish the required pressure differential. The plurality of
inlet ports 17 on one side of the boilerless steamer apparatus 1
and the fan 4 on the other side, the steam entering the cooking
space 10 directly impacts the food product and is drawn across the
food product by the fan 4. In the preferred embodiment, there are
between 2 to 4 substantially vertical tube steam delivery path 23
providing steam at various levels in the cooking space 10. The
substantially vertical steam paths 23 are preferably round in
diameter and between 3/4 to 11/2 inch I.D. The substantially
vertical tube steam delivery paths 23 must be of the designated
size to preferably provide between 7 lbs./hour/pan to 10 lbs./hour
to the cooking space 10.
[0029] In an alternative embodiment, the steam routing path may be
formed internal to the steamer cavity walls 39 such as by
incorporating the pathway, into the interior sheet metal of steamer
cavity 40.
[0030] Fourth, the removable steam lid 6 catches most of the steam
condensate and food product spills. Keeping the condensate and food
spills from entering the steam generator space 11 reduces the
contamination of the water 34. Many contaminants cause the boiling
water to foam and transfer flavors between food products.
[0031] The plurality of heating elements 9 provides heat to
generate steam. Water level sensors 8 detect high and low
operational water levels. Condensate cup 7 collects most condensed
steam from the cooking process. The condensate cup 7 is a means to
remove condensate from the cooking space. Overflow tube 15 reduces
water from spilling out of boilerless steamer apparatus 1.
[0032] The function of the condensate cup 7 to receive the
condensate and food spills from the removable steam lid 6. The
condensate cup 7 and related drainage tubes provide a means to
remove most condensation from the cooking space 10. After receipt
of the liquids, the condensate cup 7 ducts these fluids to an
attached condensate drain tube 16 connected to the drain box 27. It
is also the third leg of support for the removable steam lid 6. In
the preferred embodiment, the condensate cup 7 is mounted on the
vertical wall along with the water level sensors 8.
[0033] Water level is maintained by the water level sensors 8. If
the water level sensors 8 fail then maximum water level is
controlled by overflow tube 15. Water level inside the steam
generating space 11 is detected by two water level sensors 8. The
upper probe provides water level information to the control board
so that normal operating water level is maintained. The lower probe
serves as a safety device. When this lower probe does not sense the
presence of water in the steam generator, the water level board
will disable the steamer and notify the user that service is
required.
[0034] If the steam generating space 11 needs to be drained for
cleaning then water can be drained via cavity drain 29. Power and
control components are secured to two electrical panel assemblies:
high voltage panel assembly 46 and low voltage panel assembly
47.
[0035] FIG. 3 shows the inside view of the left side of the
interior of the entire boilerless steamer apparatus 1. A plurality
of steam ports 19 allow steam from steam generating space 11 into
cooking space 10 at various levels through a plurality of inlet
ports 17. Steam cooking cavity vent port 18 admits spent steam to
drain box 27. The boilerless steamer apparatus 1 is connected to
drain box 27, and hence the drain during operation.
[0036] An additional safety feature of the boilerless steamer
apparatus 1 is a magnet 48 attached to the removable steam lid 6.
When the removable steam lid 6 is properly installed, a magnetic
switch 49 senses the magnetic field from magnet 48 attached to
removable steam lid 6, sends a signal to the control board and
allows the steamer to apply power to the heating elements 9 or
infrared burners 41. The proper installation of the removable steam
lid 6 is necessary so that the steam generating space 11 operates
at the proper pressure. Also, the removable steam lid 6 keeps a
user from reaching into the cavity and coming in contact with the
boiling water in the steam generating space 11.
[0037] FIG. 4 shows a view of the left side of the boilerless
steamer apparatus 1 with the outer cover and insulation removed. A
plurality of steam ports 19 connect with substantially vertical
tube steam delivery paths 23 outside the steam generating space 11.
Substantially vertical tube steam delivery paths 23 further
connects the plurality of inlet ports 17 are positioned to deliver
steam to the cooking space 10 at various levels. Steam vents
through steam cooking cavity vent port 18 into substantially
vertical tube steam vent path 22 which in turn connects to the
drain tube assembly 25. Vacuum breaker 21 prevents collapse of the
steamer cavity 40 during cool water refill or rapid door
closing.
[0038] FIG. 5 shows a view of the right side with the outer cover
and insulation removed. Refill water enters the steam generating
space 11 through cavity drain 29. Cooking juices and condensed
steam drain onto removable steam lid 6 and collect in condensate
cup 7, pass through connecting line 16 and into drain box 27.
Fluids exit the boilerless steamer apparatus 1 through drain tube
assembly 25. Fresh water enters the steam generating space 11
through water inlet tube 20 during operation. This fresh water is
piped through the cavity drain 29 in order to automatically remove
debris which may obstruct the cavity drain.
[0039] FIG. 6 shows a section view from the rear. A plurality of
heating elements 9 cause water to boil in steam generating space
11. The heating elements 9 are nonsubmerged. Steam passes through a
plurality of steam ports 19 up into the cooking space 10. Removable
steam lid 6 directs condensate drips into condensate cup 7. The
plurality of heating elements 9 shown in FIG. 6 forms multiple, low
watt density heater strips. The quantity of heating elements can
vary from 3 to 24 depending on the steamer cavity 40 size and power
required.
[0040] By using multiple elements, the watt density of each heating
element 9 is reduced thus extending the life of each element. If a
heating element from the plurality of heating elements 9 need to be
replaced then only the bad element is replaced. Also, to facilitate
the low watt density element, the cavity chamber has been extended
significantly. Most steamer cavities are shaped to hold only the
size of the pan. A feature of the boilerless steamer apparatus is
the steamer cavity has been increased by about 1/4 to give the
elements area to heat. This improves the thermal inertia of the
cooking space 10. The extra volume allows the water reservoir to be
large which in turn minimizes the quench effect during the addition
of water. The heat transfer area has to be large to execute a
boilerless gas and electric unit. In this invention, the steamer
cavity is shaped to accommodate a sufficient number of electric
heating elements to provide an element watt density of less than 35
watts per sq. inch. Similarly, the steamer cavity of this invention
is shaped to accommodate a sufficient number of gas burners to
provide between 48,000-75,000 BTU/hour.
[0041] FIG. 7 illustrates removable steam lid 6 with drain tube 32,
which inserts into condensate cup 7. The removable steam lid 6 has
holes 30 to prevent debris from clogging drain tube 32 of removable
steam lid 6 and drainage system down stream. The removable steam
lid 6 in one embodiment is a formed piece of sheet metal with a
shallow valley slope down to drain tube 32. A screen 30 can be used
to restrict debris from clogging drain tube 32. Edge 28 facilitates
cleaning in place by allowing a user to wipe out food particles and
other unwanted debris.
[0042] FIG. 8 is a frontal section view showing steam movement.
Steam leaves the water 34 in steam generating space 11 and travels
partly into plurality of steam ports 19 and plurality of ports 36
in shroud 37. Shroud 37 protects fan 4, supports plurality of racks
3, and contains a plurality of steam ports 36. Vented steam in
substantially vertical vent tube steam vent path 22 connects with
drain box 27 through substantially horizontal vent path 33. A gap
24 between removable steam lid 6 and steamer cavity walls 39 of the
steamer cavity 40 are preferably between 0.125 inch-0.5 inch. This
gap 24 facilitates the creation of a differential in pressure
between cooking space 10 and steam generating space 11. This
pressure differential is between 0.05 to 0.15 psi. This pressure
differential causes steam to flow via the substantially vertical
steam delivery path 23 to cooking space 10.
[0043] FIG. 9 is a right side view showing steam flowing up from
plurality of steam ports 19. Substantially vertical tube steam
delivery paths 23 into plurality of inlet ports 17. Vented steam
flows through steam cooking cavity vent port 18 and down
substantially vertical tube steam vent path 22 through drainage
system.
[0044] FIG. 10 shows a frontal view of steamer cavity 40 of
combined steam generating and cooking chamber of alternate
embodiment using infrared burners 41.
[0045] FIG. 11 shows a sectional view of the gas burners of an
alternate embodiment. Combustion chamber 43 vents to exhaust flue
44. Radiant heat generated by the burners warms conduction studs 42
which in turn help conduct heat into steam generating space 11.
[0046] FIG. 10 is a front view of an isolated steam chamber of an
alternate embodiment substituting gas burners for electronic
resistance heating element.
[0047] FIG. 11 is a partial side view taken along section line
11-11 of FIG. 10. In the gas embodiment of the boilerless steamer
apparatus 1 creates steam using infrared burners 41 and combustion
chamber 43. The infrared burners 41 use all three methods of heat
transfer (convection, conduction and radiation) to heat the water
in the steamer base 45. Convective heat transfer is achieved by a
bed of flame originating from the surface of the burners. These hot
gases impinge on the steamer base 45 which in turn heats the water.
Conductive heat transfer occurs when the burners 41 heats the
cavity base studs 42 which conduct this absorbed heat to the
steamer base 45. Radiation is the most significant mode of heat
transfer from the burners to the steamer base 45. Infrared
radiation is produced by the burner flames heating the ceramic
burners face causing them to glow and heat the steamer base 45.
[0048] The burners 41 are started by gas flow and a hot surface
igniter. Ignition is proven by a flame sensor 46. If flame is not
detected by the flame sensor 46, then the gas supply is ceased as a
safety precaution. The addition of a view port 47 aids service
personnel in determining the presence of flame. Hot gases are
removed from the combustion chamber by an attached horizontal flue
44. A vertical flue (not shown) is attached to this horizontal flue
44 to direct the hot gases upward and to a required exhaust hood,
(not shown).
EXAMPLE 1
Method of Operation
[0049] After heat is applied and the boilerless steamer apparatus 1
reaches cooking temperature, steam ready sensor 13 indicates to the
steamer control to illuminate a "READY" light located on the front
control panel. This "READY" light tells the user that the steamer
cavity 40 is at a suitable temperature to begin cooking.
[0050] The steam generating space 11 is drained at shut-down
through the cavity drain 29 which piped to a drain valve 14
connected to the drain box 27 and finally plumbed to a waste drain
via drain tube assembly 25. Waste water requires cooling to comply
with many plumbing codes, therefore tube 12 provides cooling water
to the drain box 27.
[0051] The condensate cup 7 serves to remove condensate and food
spills which are caught by the boilerless steamer apparatus 1.
These waste fluids travel through a condensate drain tube 16 to the
drain box 27.
[0052] The plurality of substantially vertical tube steam delivery
paths 23 contains a steam ready sensor 13. Vented steam is removed
from the boilerless steamer apparatus 1 by a substantially vertical
tube steam vent path 22 and horizontal vent tube 33. This vent tube
system is connected to the drain box 27.
[0053] Steamer cavity 40 pressure is controlled by a vacuum breaker
21 and an overflow tube 15. The vacuum breaker 21 prevents the
steam cavity from implosion due to negative pressure when cool
refill water enters the cavity or when the door is closed rapidly.
The overflow tube 15 also serves to keep the steamer cavity 40
pressure between 0 and 1 psi and drain excess water to the drain
box 27.
[0054] Fresh water enters the steam generating space 11 through
water inlet tube 20. This fresh water is piped through the cavity
drain 29 in order to automatically remove debris which may obstruct
the cavity drain 29.
[0055] Power and control components are secured to two electrical
panel assemblies: high voltage panel assembly 46 and low voltage
panel assembly 47. Water level inside the steam generating space 11
is detected by two water level sensors 8. The water level sensor 8
provides water level information to the control board so that
normal operating water level is maintained. The water level sensor
8 serves as a safety device. When this water level sensor 8 does
not sense the presence of water in the steam generating space 11,
the water level board will disable the steamer and notify the user
that service is required.
[0056] The boilerless steamer apparatus 1 features three methods
for cooking duration control. One is "constant on" mode. In this
mode, the operator places food product in the steamer and presses
this constant on button. The boilerless steamer apparatus 1
constant on feature will steam at full capacity until this mode is
cancelled, a different mode is selected or the steamer is turned
off. A second cooking control method is "timed" mode. In timed
mode, the operator places food product in the steamer and inputs a
cook time. The boilerless steamer apparatus 1 will then steam at
full capacity until the input time expires and then enter a
stand-by mode until this mode is cancelled, a different mode is
selected or the boilerless steamer apparatus 1 is turned off.
[0057] Another cooking control method is using steamer cavity vent
flow and pressure to determine when the cavity is producing at
maximum steam. When a control circuit senses the near maximum steam
event, the system will reduce power input and water flow. This is
useful for the end user to shut down when not in use, thus saving
water and energy. When the user wants to cook again food is loaded
into the cavity, the systems senses the change and begins to steam
again.
[0058] The electric embodiment of the boilerless steamer apparatus
1 uses 6 to 24 heating elements 9 to produce steam. Elements are
secured to the bottom of the steam generator 45 by element securing
brackets 50. Thermal energy efficiency is improved by placing
insulation 51 over the element and bracket assembly.
[0059] Although the foregoing invention has been described in some
detail by way of illustration and example for purposes of clarity
of understanding, it will be obvious that certain changes and
modifications may be practiced within the scope of the appended
claims.
* * * * *