Patent US4534118A successfully refreshed from Google Patents.
US4534118A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solar-assisted mobile food dehydrator
Assignee: SUN-FLO INTERNATIONAL Inc
•
Filing: 1982-08-30
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Granted: 1985-08-13
•
Expires: 2002-08-30
Abstract
Abstract The cost of preserving and transporting food is minimized, to the end that food may be made more widely available. A trailer, movable by a small vehicle, houses a completely self-contained food dehydration plant which can be towed to the field in order to preserve the food as soon as it is harvested. The plant dehydrates by blowing a stream of hot air over the food. In order to conserve energy, the air is preheated both in a solar collector (by sunlight) and in a heat exchanger (by exhaust air). Some air used for dehydration is not exhausted but instead is recirculated through the plant, further contributing to efficiency.
Inventors
- 👤 Marcello M. Cabus
- 👤 Billy D. Howard
- 👤 James W. Colt
- 👤 Edward S. Tuft
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:53
CPC Classifications
F; F26; F26B; F26B23/00; F26B23/001; F26B23/002; F26B19/00; F26B19/005; F26B3/00; F26B3/02; F26B3/04; F26B3/28; F26B3/283; F26B3/286; Y; Y02; Y02A; Y02A40/00; Y02A40/90; Y02A40/924; Y02A40/926; Y02B; Y02B40/00; Y02B40/18; Y02P; Y02P70/00; Y02P70/10
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
192 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, and a heater to heat the inlet gas stream; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be reheated and re-accelerated and directing the remainder to said heat exchanger means, said recirculation means including means for adjusting the relative sizes of the variable portion and the remainder in accordance with a parameter of the gas stream.
Claim 2
Dependent Claim
192 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, and a heater to heat the inlet gas stream; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be reheated and re-accelerated and directing the remainder to said heat exchanger means, said recirculation means including means for adjusting the relative sizes of the variable portion and the remainder in accordance with a parameter of the gas stream.
Claim 3
Dependent Claim
28 words
A food dehydration machine as claimed in claim 1 wherein said heating means further further comprises solar collector means for preheating the inlet gas stream using solar energy.
Claim 4
Dependent Claim
21 words
A food dehydration machine as claimed in claim 2 further comprising transport means for moving said machine to a desired location.
Claim 5
Dependent Claim
24 words
A food dehydration machine as claimed in claim 3 wherein said transport means contains all processing equipment necessary to prepare the food for dehydration.
Claim 6
Dependent Claim
33 words
A food dehydration machine as claimed in claim 4 wherein said transport means comprises power supply means for furnishing all power necessary to the operation of said processing equipment and said dehydration machine.
Claim 7
Dependent Claim
25 words
A food dehydration machine as claimed in claim 2 wherein the angle of said solar collector means in relation to the solar energy is adjustable.
Claim 8
Dependent Claim
59 words
A food dehydration machine as claimed in claim 1 or 2 wherein said recirculation means comprises a distribution damper to divide the exhaust gas stream into the portion returned to the inlet gas stream and the remainder directed to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder.
Claim 9
Dependent Claim
26 words
A food dehydration machine as claimed in claim 1 or 2 wherein said heat exchanger means includes intake channels separated from exhaust channels by polyester membranes.
Claim 10
Dependent Claim
24 words
A food dehydration machine as claimed in claim 2 or 3 further comprising support means for supporting the food within said drying tunnel means.
Claim 11
Dependent Claim
17 words
A food dehydration machine as claimed in claim 1, 2 or 3 wherein said gas is air.
Claim 12
Dependent Claim
206 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heating means connected to said intake chamber for preheating the inlet air stream using the energy from an exhaust air stream; a combustion heater to receive the inlet air stream from said heat exchanger means and to heat the inlet air stream; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream from said combustion heater and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by a parameter of the gas stream; and a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be reheated and re-accelerated.
Claim 13
Dependent Claim
206 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heating means connected to said intake chamber for preheating the inlet air stream using the energy from an exhaust air stream; a combustion heater to receive the inlet air stream from said heat exchanger means and to heat the inlet air stream; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream from said combustion heater and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by a parameter of the gas stream; and a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be reheated and re-accelerated.
Claim 14
Dependent Claim
32 words
A food dehydration machine as claimed in claim 11 further comprising solar collector means between said intake port and said heat exchanger means for preheating the inlet air stream using solar energy.
Claim 15
Dependent Claim
25 words
A food dehydration machine as claimed in claim 12 wherein the angle of said solar collector means in relation to the solar energy is adjustable.
Claim 16
Dependent Claim
194 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, and solar collector means for preheating the inlet gas stream using solar energy; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be re-accelerated and directing the remainder to said head exchanger means, said recirculation means including means for adjusting the relative sizes of the variable portion and the remainder in accordance with a parameter of the gas stream.
Claim 17
Dependent Claim
194 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, and solar collector means for preheating the inlet gas stream using solar energy; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be re-accelerated and directing the remainder to said head exchanger means, said recirculation means including means for adjusting the relative sizes of the variable portion and the remainder in accordance with a parameter of the gas stream.
Claim 18
Dependent Claim
198 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heat exchanger means connected to said intake chamber for preheating the inlet air stream using the energy from an exhaust air stream; solar collector means connected to said heat exchanger means for preheating the inlet air stream using solar energy; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determing the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by a parameter of the gas stream; and a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be re-accelerated.
Claim 19
Dependent Claim
198 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heat exchanger means connected to said intake chamber for preheating the inlet air stream using the energy from an exhaust air stream; solar collector means connected to said heat exchanger means for preheating the inlet air stream using solar energy; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determing the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by a parameter of the gas stream; and a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be re-accelerated.
Claim 20
Dependent Claim
133 words
In a food dehydration machine comprising drying tunnel means for receiving an inlet gas stream, containing food to be dehydrated, and allowing the inlet gas stream to contact the food, the gas stream upon being discharged from the drying tunnel means becoming the exhaust gas stream, a method of dehydrating the food comprising the steps of: accelerating the inlet gas stream through the drying tunnel means; dividing the exhaust gas stream into two separate parts, a variable portion and a remainder; returning the variable portion to the inlet gas stream to be re-accelerated; recovering heat from the remainder; imparting at least a portion of the recovered heat to the inlet gas stream; and adjusting the relative sizes of the variable portion and the remainder in accordance with a parameter of the gas stream.
Claim 21
Dependent Claim
133 words
In a food dehydration machine comprising drying tunnel means for receiving an inlet gas stream, containing food to be dehydrated, and allowing the inlet gas stream to contact the food, the gas stream upon being discharged from the drying tunnel means becoming the exhaust gas stream, a method of dehydrating the food comprising the steps of: accelerating the inlet gas stream through the drying tunnel means; dividing the exhaust gas stream into two separate parts, a variable portion and a remainder; returning the variable portion to the inlet gas stream to be re-accelerated; recovering heat from the remainder; imparting at least a portion of the recovered heat to the inlet gas stream; and adjusting the relative sizes of the variable portion and the remainder in accordance with a parameter of the gas stream.
Claim 22
Dependent Claim
15 words
The method of claim 16 further comprising the step of heating the inlet gas stream.
Claim 23
Dependent Claim
46 words
The method of claim 17 wherein said step of heating the inlet gas stream comprises the steps of: collecting solar energy; converting the collected solar energy to heat; and imparting at least a portion of the heat converted from solar energy in the inlet gas stream.
Claim 24
Dependent Claim
42 words
The method of claim 17 wherein said step of heating the inlet gas stream comprises the steps of: oxidizing a fuel to create heat; and imparting at least a portion of the heat created by oxidizing fuel to the inlet gas stream.
Claim 25
Dependent Claim
29 words
The method of claim 17 wherein said step of heating the inlet gas stream comprises heating the inlet gas stream to a temperature substantially no greater than 160° F.
Claim 26
Dependent Claim
27 words
The method of claim 18 wherein said step of heating the inlet gas stream further comprises heating the inlet gas stream over a variable and programmable range.
Claim 27
Dependent Claim
34 words
The method of claim 17 wherein said step of heating the inlet gas stream comprises heating the inlet gas stream while maintaining the temperature of the food substantially between 100° F. and 150° F.
Claim 28
Dependent Claim
29 words
The method of claim 22 wherein said step of heating the inlet gas stream further comprises maintaining the temperature of the food within prescribed variable and programmable temperature limits.
Claim 29
Dependent Claim
32 words
The method of claim 16 wherein said step of accelerating the inlet gas stream comprises accelerating the inlet gas stream to a velocity substantially within the range of 2 to 20 miles/hour.
Claim 30
Dependent Claim
27 words
The method of claim 24 wherein said step of accelerating the inlet gas stream further comprises accelerating the inlet gas stream to a variable and programmable velocity.
Claim 31
Dependent Claim
229 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, and a heater to heat the inlet gas stream; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be reheated and re-accelerated and directing the remainder to said heat exchanger means, said recirculation means comprising a distribution damper to divide the exhaust stream into the portion returned to the inlet gas stream and the remainder directed to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by the humidity of the exhaust gas stream.
Claim 32
Dependent Claim
229 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, and a heater to heat the inlet gas stream; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be reheated and re-accelerated and directing the remainder to said heat exchanger means, said recirculation means comprising a distribution damper to divide the exhaust stream into the portion returned to the inlet gas stream and the remainder directed to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by the humidity of the exhaust gas stream.
Claim 33
Dependent Claim
27 words
A food dehydration machine as claimed in claim 26 wherein said heating means further comprises solar collector means for preheating the inlet gas stream using solar energy.
Claim 34
Dependent Claim
279 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, solar collector means for preheating the inlet gas stream using solar energy, and a heater to heat the inlet gas stream; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; support means for supporting the food within said drying tunnel means, said support means comprising at least one cart movable within said drying tunnel means; a ram positioned to move said cart within said drying tunnel means; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be reheated and re-accelerated and directing the remainder to said heat exchanger means, said recirculation means comprising a distribution damper to divide the exhaust gas stream into the portion returned to the inlet gas stream and the remainder directed to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by the humidity of the exhaust gas stream.
Claim 35
Dependent Claim
279 words
A food dehydration machine comprising: an intake chamber to receive an inlet gas stream; heating means connected to said intake chamber for heating the inlet gas stream, said heating means comprising heat exchanger means for preheating the inlet gas stream using the energy from an exhaust gas stream, solar collector means for preheating the inlet gas stream using solar energy, and a heater to heat the inlet gas stream; blower means for accelerating the inlet gas stream; drying tunnel means connected to said intake chamber for containing food to be dehydrated and for receiving the heated inlet gas stream and allowing the inlet gas stream to contact the food, the gas stream after contacting the food becoming the exhaust gas stream; support means for supporting the food within said drying tunnel means, said support means comprising at least one cart movable within said drying tunnel means; a ram positioned to move said cart within said drying tunnel means; and recirculation means connected to said drying tunnel means and said heat exchanger means for dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, and for returning the variable portion to mix with the inlet gas stream to be reheated and re-accelerated and directing the remainder to said heat exchanger means, said recirculation means comprising a distribution damper to divide the exhaust gas stream into the portion returned to the inlet gas stream and the remainder directed to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by the humidity of the exhaust gas stream.
Claim 36
Dependent Claim
21 words
A food dehydration machine as claimed in claim 28 further comprising transport means for moving said machine to a desired location.
Claim 37
Dependent Claim
181 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heating means connected to said intake chabmer for preheating the inlet air stream using the energy from an exhaust air stream; a combustion heater to receive the inlet air stream from said heat exchanger means and to heat the inlet air stream; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream from said combustion heater and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by the humidity of the exhaust air stream; and
Claim 38
Dependent Claim
181 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heating means connected to said intake chabmer for preheating the inlet air stream using the energy from an exhaust air stream; a combustion heater to receive the inlet air stream from said heat exchanger means and to heat the inlet air stream; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream from said combustion heater and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder, wherein the position of said distribution damper is determined by the humidity of the exhaust air stream; and
Claim 39
Dependent Claim
26 words
a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be reheated and reaccelerated.
Claim 40
Dependent Claim
26 words
a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be reheated and reaccelerated.
Claim 41
Dependent Claim
39 words
A food dehydration machine as claimed in claim 30 further comprising: a humidistat to supply a signal representative of the humidity of the exhaust air stream; and a motor responsive to the signal to automatically position said distribution damper.
Claim 42
Dependent Claim
230 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heating means connected to said intake chamber for preheating the inlet air stream using the energy from an exhaust air stream; a combustion heater to receive the inlet air stream from said heat exchanger means and to heat the inlet air stream; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream from said combustion heater and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder; and a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be reheated and reaccelerated; an electric motor to drive said fan; a generator to supply electrical power to said motor; an internal combustion engine to drive said generator; and fuel supply means for supplying fuel to said internal combustion engine and said combustion heater.
Claim 43
Dependent Claim
230 words
A mobile food dehydration machine comprising: an intake chamber to receive an inlet air stream; heating means connected to said intake chamber for preheating the inlet air stream using the energy from an exhaust air stream; a combustion heater to receive the inlet air stream from said heat exchanger means and to heat the inlet air stream; a fan to accelerate the inlet air stream; drying tunnel means for containing food to be dehydrated and for receiving the heated inlet air stream from said combustion heater and allowing the inlet air stream to contact the food, the air stream after contacting the food becoming the exhaust air stream; a distribution damper adjacent said drying tunnel means to divide the exhaust air stream into two separate parts, a variable portion and a remainder, and to divert the variable portion and direct the remainder to said heat exchanger means, the position of said distribution damper determining the relative sizes of the portion and the remainder; and a recirculation duct positioned to return the diverted portion of the exhaust air stream to mix with the inlet air stream to be reheated and reaccelerated; an electric motor to drive said fan; a generator to supply electrical power to said motor; an internal combustion engine to drive said generator; and fuel supply means for supplying fuel to said internal combustion engine and said combustion heater.
Claim 44
Dependent Claim
32 words
A food dehydration machine as claimed in claim 32 further comprising solar collector means between said intake chamber and said heat exchanger means for preheating the inlet air stream using solar energy.
Claim 45
Dependent Claim
132 words
In a food dehydration machine comprising drying tunnel means for receiving an inlet gas stream, containing food to be dehydrated, and allowing the inlet gas stream to contact the food, the gas stream upon being discharged from the drying tunnel means becoming an exhaust gas stream, a method of dehydrating the food comprising the steps of: accelerating the inlet gas stream through the drying tunnel means; determining the humidity of the exhaust gas stream; dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, the variable portion being variable in accordance with the determined humidity; returning the variable portion to the inlet gas stream to be reaccelerated; recovering heat from the remainder; and imparting at least a portion of the recovered heat to the inlet gas stream.
Claim 46
Dependent Claim
132 words
In a food dehydration machine comprising drying tunnel means for receiving an inlet gas stream, containing food to be dehydrated, and allowing the inlet gas stream to contact the food, the gas stream upon being discharged from the drying tunnel means becoming an exhaust gas stream, a method of dehydrating the food comprising the steps of: accelerating the inlet gas stream through the drying tunnel means; determining the humidity of the exhaust gas stream; dividing the exhaust gas stream into two separate parts, a variable portion and a remainder, the variable portion being variable in accordance with the determined humidity; returning the variable portion to the inlet gas stream to be reaccelerated; recovering heat from the remainder; and imparting at least a portion of the recovered heat to the inlet gas stream.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |