WO2000043717A1 - Drying apparatus and methods - Google Patents

Drying apparatus and methods Download PDF

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Publication number
WO2000043717A1
WO2000043717A1 PCT/AU2000/000037 AU0000037W WO0043717A1 WO 2000043717 A1 WO2000043717 A1 WO 2000043717A1 AU 0000037 W AU0000037 W AU 0000037W WO 0043717 A1 WO0043717 A1 WO 0043717A1
Authority
WO
WIPO (PCT)
Prior art keywords
drying chamber
controlled environment
objects
materials
drying
Prior art date
Application number
PCT/AU2000/000037
Other languages
French (fr)
Inventor
Allan Reginald Fry
Richard Arthur Anderson
Original Assignee
Heatwave Systems International Pty. Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Heatwave Systems International Pty. Ltd. filed Critical Heatwave Systems International Pty. Ltd.
Priority to AU26464/00A priority Critical patent/AU2646400A/en
Publication of WO2000043717A1 publication Critical patent/WO2000043717A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
    • F26B21/06—Controlling, e.g. regulating, parameters of gas supply
    • F26B21/08—Humidity
    • F26B21/086—Humidity by condensing the moisture in the drying medium, which may be recycled, e.g. using a heat pump cycle
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
    • A23L3/40—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by drying or kilning; Subsequent reconstitution
    • A23L3/54—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by drying or kilning; Subsequent reconstitution using irradiation or electrical treatment, e.g. ultrasonic waves
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23N—MACHINES OR APPARATUS FOR TREATING HARVESTED FRUIT, VEGETABLES OR FLOWER BULBS IN BULK, NOT OTHERWISE PROVIDED FOR; PEELING VEGETABLES OR FRUIT IN BULK; APPARATUS FOR PREPARING ANIMAL FEEDING- STUFFS
    • A23N12/00—Machines for cleaning, blanching, drying or roasting fruits or vegetables, e.g. coffee, cocoa, nuts
    • A23N12/08—Machines for cleaning, blanching, drying or roasting fruits or vegetables, e.g. coffee, cocoa, nuts for drying or roasting
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
    • F26B11/18—Machines or apparatus for drying solid materials or objects with movement which is non-progressive on or in moving dishes, trays, pans, or other mainly-open receptacles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
    • F26B21/14—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects using gases or vapours other than air or steam, e.g. inert gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B3/00—Drying solid materials or objects by processes involving the application of heat
    • F26B3/32—Drying solid materials or objects by processes involving the application of heat by development of heat within the materials or objects to be dried, e.g. by fermentation or other microbiological action
    • F26B3/34—Drying solid materials or objects by processes involving the application of heat by development of heat within the materials or objects to be dried, e.g. by fermentation or other microbiological action by using electrical effects
    • F26B3/343—Drying solid materials or objects by processes involving the application of heat by development of heat within the materials or objects to be dried, e.g. by fermentation or other microbiological action by using electrical effects in combination with convection
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B5/00—Drying solid materials or objects by processes not involving the application of heat
    • F26B5/04—Drying solid materials or objects by processes not involving the application of heat by evaporation or sublimation of moisture under reduced pressure, e.g. in a vacuum
    • F26B5/048—Drying solid materials or objects by processes not involving the application of heat by evaporation or sublimation of moisture under reduced pressure, e.g. in a vacuum in combination with heat developed by electro-magnetic means, e.g. microwave energy

Definitions

  • TECHNICAL FIELD relates to methods and apparatus for drying materials or objects. BACKGROUND ART
  • the method may further include the step of removing moisture from the controlled environment.
  • Gas can be circulated within the drying chamber and the controlled environment by a forced draft system.
  • the method may include the step of pre-heating gas within the controlled environment prior to its reintroduction into the drying chamber.
  • the method may include the step of continuously rotating the materials or objects within the drying chamber.
  • an apparatus for drying materials or objects comprising; a drying chamber, a housing providing controlled environment communicable with the drying chamber, a microwave heat source communicable with the drying chamber, cooling means disposed with the housing, and means for circulating a gas throughout the drying chamber and housing.
  • Gas circulating within the housing can be cooled and then reheated prior to re-introduction into the drying chamber.
  • Means for trapping and removing moisture from the housing can be provided.
  • Means for conveying materials or objects within the drying chamber can be provided.
  • the drying chamber can be positioned within the housing and is provided with an external access door.
  • a turntable can be positioned on the base of the drying chamber.
  • Microwave energy can be introduced into the drying chamber via a microwave distribution device.
  • a microwave generator can be positioned externally on the housing.
  • the apparatus can include internal temperature and humidity sensors and control means for controlling heating and cooling within the apparatus.
  • the drying chamber walls can be provided with microwave screens via which gases can be extracted and introduced.
  • heating by microwave energy embraces heating, such as induction or dielectric heating of material resulting from the placing of the material in a microwave energy field.
  • microwave energy refers to electromagnetic energy in the microwave spectrum.
  • heat pump drier refers to the method of reducing the humidity of a gas (typically air) by using a refrigerating device. Such devices reduce the temperature of a portion of the gas, using a heat exchanger, causing the gas temperature to drop below its dew point being the temperature at which droplets of moisture form in the gas. In this situation droplets cling to the surface of a cooling apparatus, and subsequently drain from it. The heat removed from the gas in the cold element may be transferred to a hot element which re-heats the gas, creating warm relatively dry air.
  • the apparatus may comprise a conveyor or racked trays on to which the material to be dried is spread.
  • the trays or conveyor may be contained in a chamber from which no microwave energy escapes.
  • Single or multiple microwave generators may be used to deliver energy to the chamber through waveguides and a distribution method that ensures even energy distribution.
  • Materials may be continually moved inside the chamber to improve the distribution of microwave energy to the material. Even heating of the material results.
  • Air or another drying medium e.g. nitrogen
  • the drying medium may be circulated in a closed loop through a heat pump drying system, and back to the chamber, picking up liquid from the surface of the material, and extracting it in the heat pump drier section.
  • sensors for drying medium temperatures and humidity, both in and out of the chamber, and product weight and temperature would normally be needed.
  • the particular frequency of the microwave energy may be selected to provide optimum drying of the specific material being dried.
  • Figure 1 is a schematic illustration of the fundamental componentry and one possible layout for a drying apparatus according to the present invention
  • Figures 2, 3 and 4 are plan, side and front layout drawings of an apparatus according to the present invention
  • Figure 5 is a plan layout drawing of a further form of apparatus according to the present invention.
  • Figures 6 and 6a illustrate the results of preliminary drying trials using the apparatus of the present invention.
  • a microwave generator 3 (typically a magnetron) produces microwave energy which is fed through a waveguide 4 and distributed evenly in the chamber via distributor 2.
  • the microwave energy is contained inside the chamber by a door, chamber walls, and vent screens 5.
  • Air is forced through the chamber and over the food by fans 6, 7, via vent screens 5, the air picks up moisture as it passes over the surface of the food, and continues around the closed system contained by the housing 16.
  • a Refrigeration unit 11 is connected to cooling element 8, and heating element 12, by piping 17.
  • a fan 6 forces a portion of the circulating air through cooling element 8, which reduces the temperature of the air passing through it to a temperature below its dew point. Excess moisture in the air forms droplets on the cooling element 8, which is collected in collector 13, and drains through drain 14 as waste water.
  • This cold moisture-reduced air then mixes with the remainder of the circulating air, and passes through fans 7, to be reheated by heating element 12. Warm relatively dry air is produced, which is in an ideal state for drying. The air may then be circulated back through the chamber, where it again picks up moisture. The temperature and humidity of air at specific points around the loop may be monitored and controlled by computer control (not shown) to provide optimum drying efficiency.
  • Optional recuperator elements 10 and 9 may have circulating water between them. Elements 10 pick up heat from the air from fan 6, which is transferred to element 9, via water piping, where it looses the heat to the cold air exiting from cooling element 8. The cool water passes back to element 10, which pre-cools the air reaching cooling element 8. This improves the efficiency of the cooling element 8, removing much more moisture than would otherwise be removed.
  • the apparatus illustrated comprises a generally cylindrical drying chamber indicated by arrow 20, a housing 21 facilitating the provision of an internal controlled environment 22 communicable with the interiors of the drying chamber via microwave screens 23.
  • Fans 24 and 25 are positioned within the housing and are operable to provide a circulating air flow as indicated by the path arrows of figure 4.
  • An externally mounted microwave generator 26 distributes microwave energy to the interiors of the drying chamber 21 via a tubular and apertured distributor/waveguide device 27.
  • An evaporator 28 is positioned downstream of the fan 24 with adjacent recuperator units 20 in line with the axis of the fan 24.
  • the function of the evaporator 28 and recuperator units 28, 29 is to cool the fan forced air and to remove moisture from the air as a result of its temperature being lowered.
  • a hot coil condenser 30 is positioned downstream of the fan 25 and can be to reheat air just prior to its reintroduction into the drying chamber 20.
  • a turntable 31 rotatable by a motor 32 is provided at the base of the drying chamber. Stacks of trays (not shown) containing materials or objects to be dried can be placed on the turntable 31 and the turntable rotated to enhance heat transfer within the drying chamber.
  • Electrical and control equipment can be housed in a cabinet 34.
  • An arcuate shaped hinged door 35 provides access to the interiors of the drying cabinet. Depending on the materials or objects being processed the components of the apparatus may be individually or selectively operated.
  • Figure 5 of the drawings illustrates a modified form of apparatus according to the present invention in which heat transfer components of the apparatus are positioned within a cylindrical pressure chamber 36.
  • the apparatus includes all of the components previously described in relation to the figure 2 to 4 embodiment at the invention and similar numerals are used to identify same.
  • Pressures within the pressure chamber can be altered to provide further options in relation to the processing of materials and objects within the drying chamber.
  • temperature and humidity sensors 37 can be provided for monitoring the input and output air temperatures and humidities.
  • ducting 38 can be provided between the fan 24 and the evaporator 28 to encourage a directional air flows.
  • Figures 6 and 6a of the drawings are charts showing drying trial results on tomatoes and chillies.
  • the tests monitored temperatures adjacent to the screens of the drying chambers of the apparatus.
  • the microwave heaters were operated at full power until a predetermined weight reduction of the dried material was achieved and the microwave power is reduced for a final period.
  • the time required to produce the required degree of dehydration was fifty percent less than that required for conventional equipment and obtained at an overall saving on comparative energy costs of more than fifty percent.
  • the present invention is not only faster than conventional heat pump systems, but is much more efficient in its use of energy. It can dry material at reduced temperatures, and because of its closed loop system, can dry equally well in high humidity environments. There are no polluting and/or green house gases or waste produced by the system.
  • the advantage of this invention is that it greatly improves the transfer and subsequent release of the liquid contained in the material being dried, by heating the product uniformly with the application of microwave energy.
  • the release of liquid contained in the material is significantly enhanced, and therefore drying time and energy usage significantly reduced.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Molecular Biology (AREA)
  • Chemical & Material Sciences (AREA)
  • Microbiology (AREA)
  • Food Science & Technology (AREA)
  • Polymers & Plastics (AREA)
  • Toxicology (AREA)
  • Biomedical Technology (AREA)
  • Biotechnology (AREA)
  • Nutrition Science (AREA)
  • Drying Of Solid Materials (AREA)

Abstract

A method and apparatus is disclosed for drying objects or materials using microwave energy. The microwave energy raises the temperature of the objects or materials (1) in a drying chamber (16) causing moisture to be released from the objects or materials. The drying chamber is supplied with a steam of dehumidified air which picks up the moisture from the surface of the objects or materials. This air stream is then passed to a dehumidifying unit (8, 9, 10, 11) which removes the moisture from the air stream which is then recirculated back through the drying chamber. The air may be reheated (12) before being reintroduced into to the drying chamber.

Description

DRYING APPARATUS AND METHODS
TECHNICAL FIELD THIS INVENTION relates to methods and apparatus for drying materials or objects. BACKGROUND ART
In a conventional heat pump drier materials are dried by exposure to warm dry air which removes liquid from the surfaces of the material. A problem of this method is that often the material retains the liquid contained in the center of its mass, by either a reluctance to transfer the liquid to the exposed surfaces, or the drying material forming a skin-like barrier in its surface.
It is an object of the present invention to provide drying apparatus and methods which will improve the efficiency of drying processes for a range of materials and objects. Further objects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
DISCLOSURE OF INVENTION According to the present invention there is provided a method of drying materials or objects comprising the steps of:
(a) placing the materials or objects in a drying chamber which is communicable with a controlled environment,
(b) microwave heating the materials or objects within the drying chamber, (c) circulating gas between the controlled environment and the drying chamber, and (d) cooling gas within the controlled environment.
The method may further include the step of removing moisture from the controlled environment. Gas can be circulated within the drying chamber and the controlled environment by a forced draft system.
The method may include the step of pre-heating gas within the controlled environment prior to its reintroduction into the drying chamber.
The method may include the step of continuously rotating the materials or objects within the drying chamber.
After an initial drying phase pressures within the controlled environment may be reduced.
According to a further aspect of the present invention there is provided an apparatus for drying materials or objects comprising; a drying chamber, a housing providing controlled environment communicable with the drying chamber, a microwave heat source communicable with the drying chamber, cooling means disposed with the housing, and means for circulating a gas throughout the drying chamber and housing.
Gas circulating within the housing can be cooled and then reheated prior to re-introduction into the drying chamber.
Means for trapping and removing moisture from the housing can be provided. Means for conveying materials or objects within the drying chamber can be provided.
The drying chamber can be positioned within the housing and is provided with an external access door.
A turntable can be positioned on the base of the drying chamber.
Microwave energy can be introduced into the drying chamber via a microwave distribution device.
A microwave generator can be positioned externally on the housing. The apparatus can include internal temperature and humidity sensors and control means for controlling heating and cooling within the apparatus. The drying chamber walls can be provided with microwave screens via which gases can be extracted and introduced.
The term "heating by microwave energy" herein embraces heating, such as induction or dielectric heating of material resulting from the placing of the material in a microwave energy field.
The term "microwave energy" herein refers to electromagnetic energy in the microwave spectrum.
The term "heat pump drier" refers to the method of reducing the humidity of a gas (typically air) by using a refrigerating device. Such devices reduce the temperature of a portion of the gas, using a heat exchanger, causing the gas temperature to drop below its dew point being the temperature at which droplets of moisture form in the gas. In this situation droplets cling to the surface of a cooling apparatus, and subsequently drain from it. The heat removed from the gas in the cold element may be transferred to a hot element which re-heats the gas, creating warm relatively dry air.
According to a still further aspect of the present invention the apparatus may comprise a conveyor or racked trays on to which the material to be dried is spread. The trays or conveyor may be contained in a chamber from which no microwave energy escapes.
Single or multiple microwave generators may be used to deliver energy to the chamber through waveguides and a distribution method that ensures even energy distribution.
Materials may be continually moved inside the chamber to improve the distribution of microwave energy to the material. Even heating of the material results.
Air or another drying medium, e.g. nitrogen, may be forced by fans, over the surface of the material or objects to be dried, through vents in the chamber. The drying medium may be circulated in a closed loop through a heat pump drying system, and back to the chamber, picking up liquid from the surface of the material, and extracting it in the heat pump drier section. To allow proper control of the drying process, sensors for drying medium temperatures and humidity, both in and out of the chamber, and product weight and temperature would normally be needed.
The particular frequency of the microwave energy may be selected to provide optimum drying of the specific material being dried.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of the fundamental componentry and one possible layout for a drying apparatus according to the present invention, and Figures 2, 3 and 4 are plan, side and front layout drawings of an apparatus according to the present invention, and
Figure 5 is a plan layout drawing of a further form of apparatus according to the present invention, and
Figures 6 and 6a illustrate the results of preliminary drying trials using the apparatus of the present invention.
With respect to figure 1 objects such as whole, diced, sliced or pureed fruit, herbs, meat or other product may be placed on the rotating stacking trays 1. A microwave generator 3 (typically a magnetron) produces microwave energy which is fed through a waveguide 4 and distributed evenly in the chamber via distributor 2. The microwave energy is contained inside the chamber by a door, chamber walls, and vent screens 5.
The energy heats the food causing it to release moisture from within.
Air is forced through the chamber and over the food by fans 6, 7, via vent screens 5, the air picks up moisture as it passes over the surface of the food, and continues around the closed system contained by the housing 16.
A Refrigeration unit 11 is connected to cooling element 8, and heating element 12, by piping 17. A fan 6 forces a portion of the circulating air through cooling element 8, which reduces the temperature of the air passing through it to a temperature below its dew point. Excess moisture in the air forms droplets on the cooling element 8, which is collected in collector 13, and drains through drain 14 as waste water.
This cold moisture-reduced air then mixes with the remainder of the circulating air, and passes through fans 7, to be reheated by heating element 12. Warm relatively dry air is produced, which is in an ideal state for drying. The air may then be circulated back through the chamber, where it again picks up moisture. The temperature and humidity of air at specific points around the loop may be monitored and controlled by computer control (not shown) to provide optimum drying efficiency.
Optional recuperator elements 10 and 9 may have circulating water between them. Elements 10 pick up heat from the air from fan 6, which is transferred to element 9, via water piping, where it looses the heat to the cold air exiting from cooling element 8. The cool water passes back to element 10, which pre-cools the air reaching cooling element 8. This improves the efficiency of the cooling element 8, removing much more moisture than would otherwise be removed.
With respect to figures 2 to 4 of the drawings the apparatus illustrated comprises a generally cylindrical drying chamber indicated by arrow 20, a housing 21 facilitating the provision of an internal controlled environment 22 communicable with the interiors of the drying chamber via microwave screens 23.
Fans 24 and 25 are positioned within the housing and are operable to provide a circulating air flow as indicated by the path arrows of figure 4.
An externally mounted microwave generator 26 distributes microwave energy to the interiors of the drying chamber 21 via a tubular and apertured distributor/waveguide device 27.
An evaporator 28 is positioned downstream of the fan 24 with adjacent recuperator units 20 in line with the axis of the fan 24. The function of the evaporator 28 and recuperator units 28, 29 is to cool the fan forced air and to remove moisture from the air as a result of its temperature being lowered.
A hot coil condenser 30 is positioned downstream of the fan 25 and can be to reheat air just prior to its reintroduction into the drying chamber 20.
At the base of the drying chamber a turntable 31 rotatable by a motor 32 is provided. Stacks of trays (not shown) containing materials or objects to be dried can be placed on the turntable 31 and the turntable rotated to enhance heat transfer within the drying chamber.
Electrical and control equipment can be housed in a cabinet 34.
An arcuate shaped hinged door 35 provides access to the interiors of the drying cabinet. Depending on the materials or objects being processed the components of the apparatus may be individually or selectively operated.
Figure 5 of the drawings illustrates a modified form of apparatus according to the present invention in which heat transfer components of the apparatus are positioned within a cylindrical pressure chamber 36. The apparatus includes all of the components previously described in relation to the figure 2 to 4 embodiment at the invention and similar numerals are used to identify same.
Pressures within the pressure chamber can be altered to provide further options in relation to the processing of materials and objects within the drying chamber.
In both of the apparatus described temperature and humidity sensors 37 can be provided for monitoring the input and output air temperatures and humidities.
In the figure 5 embodiment ducting 38 can be provided between the fan 24 and the evaporator 28 to encourage a directional air flows.
Figures 6 and 6a of the drawings are charts showing drying trial results on tomatoes and chillies. The tests monitored temperatures adjacent to the screens of the drying chambers of the apparatus. The microwave heaters were operated at full power until a predetermined weight reduction of the dried material was achieved and the microwave power is reduced for a final period. In each case the time required to produce the required degree of dehydration was fifty percent less than that required for conventional equipment and obtained at an overall saving on comparative energy costs of more than fifty percent.
The present invention is not only faster than conventional heat pump systems, but is much more efficient in its use of energy. It can dry material at reduced temperatures, and because of its closed loop system, can dry equally well in high humidity environments. There are no polluting and/or green house gases or waste produced by the system.
The advantage of this invention is that it greatly improves the transfer and subsequent release of the liquid contained in the material being dried, by heating the product uniformly with the application of microwave energy. The release of liquid contained in the material is significantly enhanced, and therefore drying time and energy usage significantly reduced.
Aspects of the present invention have been described by way of example only and it will be appreciated that modifications and additions thereto may be made without departing from the scope thereof as defined in the appended claims.

Claims

CLAIMS:
1. A method of drying materials or objects comprising the steps of:
(a) placing the materials or objects in a drying chamber which is communicable with a controlled environment, (b) microwave heating the materials or objects within the drying chamber,
(c) circulating gas between the controlled environment and the drying chamber, and
(d) cooling gas within the controlled environment.
2. A method as claimed in claim 1 including the step of removing moisture from the controlled environment.
3. A method as claimed in claim 1 gas is circulated within the drying chamber and the controlled environment by a forced draft system.
4. A method as claimed in claim 1 including the step of pre-heating gas within the controlled environment prior to its reintroduction into the drying chamber.
5. A method as claimed in claim 1 including the step of continuously rotating the materials or objects within the drying chamber.
6. A method according to claim 1 including the subsequent processing steps of reducing pressures within the controlled environment.
7. A method according to claim 6 wherein the pressures within the controlled environment are reduced in stages.
8. A method as claimed in claim 1 including the steps introducing a gas into the controlled environment.
9. Apparatus for drying materials or objects comprising; a drying chamber, a housing providing controlled environment communicable with the drying chamber, a microwave heat source communicable with the drying chamber, cooling means disposed with the housing, and means for circulating a gas throughout the drying chamber and housing.
10. Apparatus as claimed in claim 9 wherein gas circulating within the housing is cooled and then reheated prior to re-introduction into the drying chamber.
11. Apparatus as claimed in claim 9 including means for trapping and removing moisture from the housing.
12. Apparatus as claimed in claim 9 including means for conveying materials or objects within the drying chamber.
13. Apparatus as claimed in claim 9 wherein the drying chamber is positioned within the housing and is provided with an external access door.
14. Apparatus as claimed in claim 12 including a turntable positioned on the base of the drying chamber and means for rotating the turntable.
15. Apparatus as claimed in claim 9 wherein microwave energy is introduced into the drying chamber via a microwave distribution device.
16. Apparatus as claimed in claim 9 having an externally positioned microwave generator.
17. Apparatus as claimed in claim 9 including internal temperature and humidity sensors and control means for controlling heating and cooling within the apparatus.
18. Apparatus as claimed in claim 9 wherein the drying chamber walls are provided with microwave wave guide traps via which gases can be extracted and introduced.
PCT/AU2000/000037 1999-01-22 2000-01-24 Drying apparatus and methods WO2000043717A1 (en)

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AUPP8286A AUPP828699A0 (en) 1999-01-22 1999-01-22 Drying apparatus and methods
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WO2006130072A1 (en) * 2005-05-30 2006-12-07 Gisip Innovations Ab Method and means for drying using microwaves
WO2007062180A1 (en) * 2005-11-23 2007-05-31 The Sherwin-Williams Company System and method to control energy input to a material
WO2008113338A2 (en) * 2007-03-16 2008-09-25 Püschner GmbH + Co. KG Microwave vacuum drying systems and method for drying lumpy, powdery, or granulated products by means of microwaves
CN106418600A (en) * 2016-08-29 2017-02-22 无锡苏芽食品有限公司 Bean sprout cleaning device
CN110926116A (en) * 2018-09-20 2020-03-27 天津金耀集团有限公司 Drying method of solid material of steroid compound
CN110926117A (en) * 2018-09-20 2020-03-27 天津金耀集团有限公司 Drying method of pregnane steroid compound solid material
CN112262951A (en) * 2020-10-14 2021-01-26 广东美的厨房电器制造有限公司 Drying control method, cooking appliance, and computer-readable storage medium
CN112284102A (en) * 2020-11-11 2021-01-29 武金英 Even drying-machine of grain
CN113340085A (en) * 2021-06-20 2021-09-03 潍坊新普食品科技有限公司 Agricultural and sideline products drying equipment
CN115900245A (en) * 2022-11-14 2023-04-04 广东岭南制药有限公司 Chemical bulk drug drying method and drying equipment with nitrogen protection

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WO2006130072A1 (en) * 2005-05-30 2006-12-07 Gisip Innovations Ab Method and means for drying using microwaves
WO2007062180A1 (en) * 2005-11-23 2007-05-31 The Sherwin-Williams Company System and method to control energy input to a material
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WO2008113338A3 (en) * 2007-03-16 2009-04-30 Pueschner Gmbh & Co Kg Microwave vacuum drying systems and method for drying lumpy, powdery, or granulated products by means of microwaves
CN106418600A (en) * 2016-08-29 2017-02-22 无锡苏芽食品有限公司 Bean sprout cleaning device
CN110926117A (en) * 2018-09-20 2020-03-27 天津金耀集团有限公司 Drying method of pregnane steroid compound solid material
CN110926116A (en) * 2018-09-20 2020-03-27 天津金耀集团有限公司 Drying method of solid material of steroid compound
CN112262951A (en) * 2020-10-14 2021-01-26 广东美的厨房电器制造有限公司 Drying control method, cooking appliance, and computer-readable storage medium
CN112262951B (en) * 2020-10-14 2023-09-22 广东美的厨房电器制造有限公司 Drying control method, cooking appliance and computer readable storage medium
CN112284102A (en) * 2020-11-11 2021-01-29 武金英 Even drying-machine of grain
CN113340085A (en) * 2021-06-20 2021-09-03 潍坊新普食品科技有限公司 Agricultural and sideline products drying equipment
CN113340085B (en) * 2021-06-20 2022-08-26 浙江耕盛堂生态农业有限公司 Agricultural and sideline products drying equipment
CN115900245A (en) * 2022-11-14 2023-04-04 广东岭南制药有限公司 Chemical bulk drug drying method and drying equipment with nitrogen protection

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