Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02685742 2009-10-29
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SHORTENING SAVING FRYER WITH AUTOMATIC FILTRATION
BACKGROUND OF THE INVENTION
l0
1. Field of the Invention
This disclosure relates to deep fryers for the food service industry.
More particularly, this disclosure relates to deep fryers that are capable of
ts filtering used oil to conserve the oil and to the oil filtering process.
Still more
particularly, this disclosure relates to deep fryers that are capable of
filtering used
oil to conserve the oil and to the oil filtering process wherein the process
uses
thermal sensor feedback to monitor the location of oil in the fryer.
2o 2. Description of Related Art
Deep fryers are a necessity of the food service industry and particularly
for the fast food service industry. Deep fryers use a substantial amount of
shortening or oil during the cooking process. During the cooking process much
25 of the oil is absorbed by a food product, resulting in loss of oil volume.
The
remaining oil can become filled with debris due to constant use. Accordingly,
there is a need to extend the usable life of the unabsorbed oil and to keep
the
unused oil clean during the cooking process.
30 Accordingly, there is a need for a deep fryer that automatically filters
used
oil in a continuous filtering loop using sensor feedback.
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SUMMARY OF THE INVENTION
The present disclosure provides for a deep fryer that filters used cooking
oil to extend the life of the cooking oil, using feedback from temperature
sensors.
s
The present disclosure aiso provides for a deep fryer that has a closed
loop oil filtering system for removing debris from the cooking oil.
The present disclosure provides for a deep fryer system that is capable of
io filtering oil using temperature sensor feedback to ensure correct location
of the
oil in the deep fryer.
The present disclosure further provides for a method of filtering cooking oil
in a deep fryer that is based on feedback from temperature sensors in the deep
15 fryer.
The present disclosure still further provides for a method of filtering
cooking oil for a plurality of fryer pots using a manifold to collect cooking
oil and a
pump associated with each deep fryer.
The present disclosure further provides for a plurality of fryer pots that are
controlled using a centralized system that uses sensory feedback to ensure
filtering steps are performed in the correct timed sequence.
The present disclosure provides for a deep fryer that provides at least two
sensors; one of the two sensors is a temperature sensor to ensure oil is in
the
deep fryer to commence the filtration cycle and the other of the two sensors
ensures that the oil has reached the desired height in the pot during the
filler
operation.
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The present disclosure still yet further provides for a deep fryer having
slots at its lower edge proximate the oil return valve to disperse oil in a
spray
pattern, the spray pattern ensures that crumbs on the bottom surface of the
deep
fryer will be flushed.
Accordingly, there is a need for a centralized process that controls the
automatic filtering operation of a deep fryer having a plurality of fryer
pots, by
using feedback from temperature sensors and timers that control the operation
of
the pumping and filling operations in each pot.
These and other further benefits and features are provided by an
automatic filtration system for cooking oil in a deep fryer having a plurality
of fryer
pots disposed in the deep fryer. Each of the plurality of fryer pots having a
first
temperature sensor, a second temperature sensor; a drain valve and return
valve. The system further has a controller that is capable of counting the
number
of cooking cycles of a particular fryer pot. After the first temperature
sensor
senses a first predetermined temperature, oil drains from the fryer pot
through
the drain valve and when the second temperature sensor senses a second
predetermined temperature the oil has substantially returned to the fryer pot
through the return valve.
An automatic filtration system for cooking oil in a deep fryer having a
deep fryer and a plurality of fryer pots disposed in the deep fryer. Each of
the
plurality of fryer pots having a first temperature sensor, a drain valve, a
second
temperature sensor, a return valve associated therewith and at least one slot
proximate the drain valve. The system further includes a controller. After the
first temperature sensor senses a first predetermined temperature, oil drains
from the fryer pot through the drain valve and when the second temperature
sensor senses a second predetermined temperature the oil returns to the fryer
pot through the return valve and the at least one slot.
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BRIEF DESCRITPION OF THE DRAWINGS
Other and further benefits, advantages and features of the present
invention will be understood by reference to the following specification in
conjunction with the accompanying drawings, in which like reference characters
denote like elements of structure and:
Fig. 1 illustrates a top perspective view of a deep fryer having two fryer
pots, each fryer pot having two temperature sensors, according to the present
invention;
Fig. 2 illustrates a front view of the deep fryer of Fig. 1 according to the
present invention;
Fig. 3 illustrates a rear view of the deep fryer of Fig. 1 showing the
manifold and filtering system components, according to the present invention;
Fig. 4 illustrates a top perspective view of the a fryer pot of Fig. 1 with a
heating element and two temperature sensors, according to the present
invention;
Fig. 5 illustrates an exploded view of a filter pan of the present invention;
Fig 6 illustrates a side view of the fryer pot of Fig. 4 having, a linear
motion
2s actuators, a drain valve and a return valve, according to the present
invention;
and
Fig. 7 illustrates a top perspective view of fryer pot of Fig. 4, having spray
slots, according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
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Referring to Fig. 1, a deep fryer is shown, and generally referred to by
reference numeral 10. Deep fryer has a housing 1.4 and two fryer pots 15 that
are each used for cooking the same or different foods. Referring to Fig. 4,
each
deep fryer pot 15 has a heating element 20 proximate to its lower surface.
Adjacent to each heating element 20 is a temperature sensor 25. Each fryer pot
also has a temperature sensor 95 located on a side wall to provide
temperature feedback as the fryer pot is filled. Sensors 25 and 95 could also
be
bi-metallic switches or any other temperature sensor capable of providing
10 temperature feedback.
Deep fryer 10 has a control panel 35 that is associated with each fryer pot
15. Control panel 35 is operatively connected to a controller 40 that monitors
the
operation of sensors and timers associated with each fryer pot 15. Controller
40
1s can accept various settings, such as, for example, temperature and timing
settings. For example, controller is 40 is capable of counting the number of
times
cooking cycles processed in a fryer pot 15. After a predetermined temperature
has been sensed, and a number of cooking cycles have been counted, the
automatic filtration can be initiated. Alternatively, after a predetermined
temperature has been sensed, the control panel 35 prompts the user with filter
cycle indicator 42, such as a lamp or an audible indicator for manual
operation of
the initiation of the automatic filtration cycle with or without a counted
number or
basket cycles. Controller 35 permits user selection of either automatic or
manual
operation.
Referring to Figs. 1 through 7, the components of the oil filtration cycle are
described in sequence. Prior to commencement of a filtration cycle, a bubbling
period of from approximately 5 to 15 second disturbs any debris that may have
come to rest on the inner surface of fryer pot 15. Air for the bubbling period
is
introduced to each fryer pot 15 by return valve 90. Each fryer pot 15 has a
drain
valve 45 that is opened and closed by a linear actuator 50. Drain valve 45 has
a
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diameter of approximately 1.25 inches in its fully open position to prevent
clogging by debris formed during the cooking process. Linear actuator 50 is
either automatically or user activated by operation of controller 40 following
prompting by filter cycle indicator lamp 42 on control panel that will
commence
draining of fryer pot 15. Beneath each fryer pot 15 is a drain manifold 55
that
collects oil from drain valves 45 of each fryer pot 15. Manifold 55 collects
oil from
each drain valve 45 in deep fryer 10. While instant deep fryer 10 shows two
fryer pots 15, there could be as many as twelve fryer pots in a deep fryer.
Oil passes from drain manifold 55 to crumb basket 65, via downspout 60.
Crumb basket 65 is a preliminary filter that removes large pieces of residual
food
product from oil. Referring to Figs. 4 and 5, after oil passes through crumb
basket 65, it is deposited in filter pan 70. As oil passes through filter pan
70, it is
pulled through a filter pad 72 located in the bottom of filter pan 70. Filter
pad 72
has a series of ridges and grooves on the lower surface thereof to permit oil
to
flow around pad 72. Filter pan 70 contains a hold down ring 71 to rriaintain
position of filter pad 72. Filter spout 75 and filter spout receiver 80
transfer
filtered oil to filter pump and motor assembly 85. Filter pump and motor
assembly 85 push oil through return valve 90, when it is in an open position,
to
return oil to fryer pot 15. Return valve 90 is opened and closed by a linear
actuator 52. Return valve 90 has a much smaller diameter of approximately 0.5
inches, in comparison to drain valve 45. Drain valve 45 must be able to
accommodate debris from bottom of fryer pot whereas, oil entering return valve
90 would have already been filtered by crumb basket 65 and filter pad 72.
Referring to Figs. 2 through 7, the process of filtering the oil will be
described. Cooking oil must be of a temperature that is warm enough to support
a filtration cycle so that oil may freely flow through filtering cycle
components.
The oil temperature must be in a range of from 270 F to 300 F. If oil is too
cool
to commence a filtration cycle, feedback from temperature sensor 25 immersed
in oil prevents initiation of an automatic filtration cycle. Alternatively, a
user can
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disable the filtration cycle and warm the oil to an acceptable temperature.
Once
the oil has reached an acceptable temperature, such as above 270 F, linear
actuator 50 can be actuated to open drain valve 45 and allow oil to drop into
manifold 55. The user can also initiate the filtration cycle after the
acceptable
temperature has been sensed, based upon the number of basket uses or if within
their judgement a filtration cycle is needed.
Once a substantial amount of oil has drained from fryer pot 15 into filter_
pan 70 from manifold 55, temperature sensor 25 in fryer pot 15 is exposed to
an
to ambient air temperature. When temperature sensor 25'senses a 10 F to 20 F
temperature drop below the set oil temperature, controller 40 energizes linear
actuator 52 to open return valve 90 and pump and motor assembly 85 are
switched on to return oil back to fryer pot 15. Sensor 25 senses a temperature
of
from approximately.250 F to 280 F. The pumping action pulls the oil through
filter pad 72 located in the bottom of filter pan 70 and forces clean filtered
oil
through return valve 90. The temperature drop sensed by sensor 25 informs
controller that oil is no longer in fryer pot 15 and that pump and motor
assembly
85 can be switched on to commence filling of fryer pot 15. Were filtration
system
only time based, the pump and motor assembly 85 may improperly commence
operation and run in the absence of oil and cause premature component failure.
After filtered oil is pushed through opened return valve 90, it is forced
through a narrow slot or several slots 100 at lower edge of fryer pot 15 and
sprayed over fryer pot lower surface. These slots are from 2 to 5 inches long,
0.05 to 0.10 inches in height, and from 1 to 5 in number. The force with which
oil
is sprayed back over lower surface of fryer pot 15 is strong enough to push
remaining heavy debris that did not initially flow through drain valve 45 at
commencement of filtering cycle, but not so great as to force oil to splash
out of
the fryer pot 15. By having an oil flow rate of approximately 3 to 9
gallons/minute
through a limited size pump and motor assembly 85, oil is prevented from
splashing out of fryer pot 15. The sprayed oil and additional debris will then
flow
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through drain valve 45. The amount of time for spraying the oil from return
valve
90 back and though the drain valve 45 is predetermined and set in controller
40
for a duration of 15 to 30 seconds. During this time, cooking oil is
repeatedly
cycied through filtration system. After 15 to 30 secondsjinear actuator 50 is
5. activated to close drain valve 45 while pump and motor assembly 85 return
oil to
fryer pot 15. The repeated or polishing cycles filters the oil to ensure that
substantially all food particles have been removed from the cooking oil and
the
fryer pot 15. The polishing filtration cycles eliminate the need for the
cooking oil
to be replaced prematurely and therefore extends the useful life of the
cooking
io oil. Further the centralized control of drain valve 45, return valve 90,
and pump
and motor assembly 85 provides, sensory feedback to ensure that the filtering
cycle is performed in the correct timed sequence.
Approximately 15 to 30 seconds after drain valve 45 is closed, heating
15 elements 20 are automatically energized to warm cooking oil that has been
returned to fryer pot 15. After 20 to 45 more seconds, the volume of cooking
oil
in fryer pot 15 is great enough so that temperature sensor 95 on fryer pot
wall is
able to sense an increase in temperature because it is immersed. When sensor
95 senses approximately 5 to 10 seconds of rising temperature the oil is
20 considered to be returned substantially to the pot. Twenty to forty-five
additional
seconds of bubbling insure that the oil is completely returned to the fryer
pot from
filter pan 70. At this time, pump and motor assembly 85 are de-energized and
linear actuator 52 is energized to close return valve 90.
25 While the instant disclosure has been described to incorporate linear
actuators, either hydraulic or pneumatic pistons could also be used for
opening
and closing the drain and return valves of the instant disclosure.
The present invention having been thus described with particular
3o reference to the preferred forms thereof, it will be obvious that various
changes
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and modifications may be made therein without departing from the spirit and
scope of the present invention as defined in the disclosure.
to
25
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