A method of uniform RF-heating within a chamber is disclosed, which includes cyclically varying electromagnetic properties of a chamber according to a plurality of configuration, transmitting an alternating RF signal about a first frequency range between a first frequency and a second frequency from a transmitter into the chamber, measuring electromagnetic power at a random receiver location in the chamber for each of the plurality of configurations and at a predetermined resolution of frequency thereby generating a statistical distribution vs. frequency, applying a statistical test to the generated statistical distribution based on a predetermined statistical function, determining a standard deviation of the average received power as a function of frequency, choosing a third frequency range associated with a standard deviation lower than a second threshold, and choosing an operational frequency in the third frequency range which provides maximum heating depending on the material being heated.

Systems and processes for use in heating articles include passing a carrier loaded with an article through a vessel inlet and into a first vessel portion and moving the loaded carrier in a first direction through the first vessel portion away from the inlet. During at least a portion of the movement through the first vessel portion, the article is contacted with a first fluid medium. The loaded carrier is moved carrier in a second direction opposite the first direction through a second vessel portion toward a vessel outlet. During at least a portion of the movement through the second vessel portion, the articles is contacted with a second fluid medium. In certain implementations, each of the first direction and the second direction are vertical.

Systems and processes for use in heating articles include passing a carrier loaded with an article through a vessel inlet and into a first vessel portion and moving the loaded carrier in a first direction through the first vessel portion away from the inlet. During at least a portion of the movement through the first vessel portion, the article is contacted with a first fluid medium. The loaded carrier is moved carrier in a second direction opposite the first direction through a second vessel portion toward a vessel outlet. During at least a portion of the movement through the second vessel portion, the articles is contacted with a second fluid medium. In certain implementations, each of the first direction and the second direction are vertical.

A microwave heat converter includes a cylindrical waveguide cavity, a non-conductive conduit, and a microwave waveguide. The non-conductive conduit is arranged to carry liquid flowing through a central area of the cylindrical waveguide cavity. The microwave waveguide is configured to deliver microwave power along the cylindrical waveguide cavity in a TE(1,1) mode to heat the liquid. The heat converter may be used in various systems such as heaters, combi boilers, and absorption refrigeration systems.

A method of drying a green ceramic honeycomb body (20) comprising: moving the body (20) through a drying system (50) comprising interconnected microwave devices (60), wherein each microwave device (D1, D2, D3) comprises an entrance (62a, 62b, 62c) located at an upstream end and an exit (64a, 64b, 64c) located at a downstream end of the microwave device (D1, D2, D3), the ends defining a downstream direction (72) and an upstream direction (74) in each of the devices (D1, D2, D3); removing moisture from the body (20) by irradiating the body (20) with microwave radiation within each of the devices (D1, D2, D3); and flowing air against the outer peripheral wall (22) of the body (20) while the body (20) is located in each of the microwave devices (D1, D2, D3). The flowing is conducted such that one or more of a supply flow and an exhaust flow of air is adjusted in at least one of the devices (D1, D2, D3) such that the air flow in the system is at a predetermined magnitude substantially in the upstream (74) or downstream direction (72).

A method of drying a green ceramic honeycomb body (20) comprising: moving the body (20) through a drying system (50) comprising interconnected microwave devices (60), wherein each microwave device (D1, D2, D3) comprises an entrance (62a, 62b, 62c) located at an upstream end and an exit (64a, 64b, 64c) located at a downstream end of the microwave device (D1, D2, D3), the ends defining a downstream direction (72) and an upstream direction (74) in each of the devices (D1, D2, D3); removing moisture from the body (20) by irradiating the body (20) with microwave radiation within each of the devices (D1, D2, D3); and flowing air against the outer peripheral wall (22) of the body (20) while the body (20) is located in each of the microwave devices (D1, D2, D3). The flowing is conducted such that one or more of a supply flow and an exhaust flow of air is adjusted in at least one of the devices (D1, D2, D3) such that the air flow in the system is at a predetermined magnitude substantially in the upstream (74) or downstream direction (72).

A food preparation appliance includes a processing mechanism, a thermal element, a sensor positioned to acquire identifying data regarding identifying characteristics of a food product to be processed by the food preparation appliance, and a processing circuit. The processing circuit is configured to receive the identifying data from the sensor, identify a type of the food product based on the identifying data, and automatically set a predefined operating parameter of at least one of the processing mechanism and the thermal element to provide target processing of the food product based on the type and the identifying characteristics.

Carriers suitable for transporting a plurality of articles through a microwave heating zone are provided. Carriers as described herein may include an outer frame and upper and lower support structures vertically spaced from one another to provide a cargo volume into which the articles are loaded. At least a portion of the upper and/or lower support structures may be formed of an electrically conductive material. Additionally, the carrier may include removable article spacing members, such as vertical spacing members and dividers, that can be selectively inserted to adjust the size and/or shaper of the cargo volume. Carriers as described herein may be configured to receive a variety of different articles, including trays and pouches, and the articles may be loaded into the carrier in a nested or overlapping manner.

A method for processing articles using a microwave heating system includes obtaining an operating profile for heating a type of article using the microwave heating system. The operating profile includes a temperature-time profile for a target F.sub.0 value and a group of set point values for achieving the temperature-time profile, the group of set point values including a target for a control parameter of the microwave heating system. Using a control system operatively coupled to the microwave heating system, the microwave heating system is operated in accordance with the group of set point values such that each of the articles achieves an F.sub.0 value that is greater than or equal to the target F.sub.0 value.

A method for processing articles using a microwave heating system includes obtaining an operating profile for heating a type of article using the microwave heating system. The operating profile includes a temperature-time profile for a target F.sub.0 value and a group of set point values for achieving the temperature-time profile, the group of set point values including a target for a control parameter of the microwave heating system. Using a control system operatively coupled to the microwave heating system, the microwave heating system is operated in accordance with the group of set point values such that each of the articles achieves an F.sub.0 value that is greater than or equal to the target F.sub.0 value.