Abstract: A commercial scale system and process for chemically modifying wood and then heating the chemically-modified wood. The system/process separates the chemical modification step from the heating step by utilizing two different vessels for the modification and heating steps. The system and process can, in certain situations, include a containment room for preventing escape of vapors from a chemical wood modification reactor, a wood heater, and/or a chemically-modified bundle of wood as the bundle is transported from the wood modification reactor to the wood heater.

Abstract: A commercial scale system and process for chemically modifying wood and then heating the chemically-modified wood. The system/process separates the chemical modification step from the heating step by utilizing two different vessels for the modification and heating steps. The system and process can, in certain situations, include a containment room for preventing escape of vapors from a chemical wood modification reactor, a wood heater, and/or a chemically-modified bundle of wood as the bundle is transported from the wood modification reactor to the wood heater.

Abstract: A microwave heater equipped with a microwave choke and suitable for heating one or more articles under vacuum. The microwave choke inhibits leakage of microwave energy between a door of the heater and a main vessel body of the heater without causing arcing at the choke, even at low pressures. In certain situations, the microwave choke can be configured with side-by-side choke cavities. In certain situations, the microwave choke can be removably coupled to the door and/or vessel body for easier fabrication, installation, and/or replacement.

Abstract: A microwave heater capable of heating a bundle of wood and equipped with an optimized system for launching and/or dispersing microwave energy. The microwave launching system can include one or more split microwave launchers at least partly disposed in the interior of the heater. The microwave dispersing system can include one or more moving reflectors for rastering microwave energy emitted from the split launchers.

Abstract: An optimized microwave barrier assembly suitable for use with a vacuum microwave heater. The barrier assembly is configured to allow microwaves to pass therethrough in a TMab mode, wherein a is 0 and b is an integer in the range of 1 to 5. The barrier assembly is also configured to maintain a pressure differential across a window of the barrier assembly. Such a configuration can reduce or eliminate arcing in the barrier assembly, even at low pressures.

Abstract: An optimized microwave barrier assembly suitable for use with a vacuum microwave heater. The barrier assembly is configured to allow microwaves to pass therethrough in a TMab mode, wherein a is 0 and b is an integer in the range of 1 to 5. The barrier assembly is also configured to maintain a pressure differential across a window of the barrier assembly. Such a configuration can reduce or eliminate arcing in the barrier assembly, even at low pressures.

Abstract: An optimized microwave barrier assembly suitable for use with a vacuum microwave heater. The barrier assembly is configured to allow microwaves to pass therethrough in a TMab mode, wherein a is 0 and b is an integer in the range of 1 to 5. The barrier assembly is also configured to maintain a pressure differential across a window of the barrier assembly. Such a configuration can reduce or eliminate arcing in the barrier assembly, even at low pressures.

Abstract: A microwave heater equipped with a microwave choke and suitable for heating one or more articles under vacuum. The microwave choke inhibits leakage of microwave energy between a door of the heater and a main vessel body of the heater without causing arcing at the choke, even at low pressures. In certain situations, the microwave choke can be configured with side-by-side choke cavities. In certain situations, the microwave choke can be removably coupled to the door and/or vessel body for easier fabrication, installation, and/or replacement.

Abstract: A commercial scale system and process for chemically modifying wood and then heating the chemically-modified wood. The system/process separates the chemical modification step from the heating step by utilizing two different vessels for the modification and heating steps. The system and process can, in certain situations, include a containment room for preventing escape of vapors from a chemical wood modification reactor, a wood heater, and/or a chemically-modified bundle of wood as the bundle is transported from the wood modification reactor to the wood heater.

Abstract: A microwave heater capable of heating a bundle of wood and equipped with an optimized system for introducing microwave energy into the heater. The system uses a high-efficiency elongated waveguide launcher having a plurality of launch openings defined in relatively thin walls. The waveguide launcher can exhibit a launch efficiency of at least 50 percent, thereby providing substantially energy savings over conventional waveguide launchers.

Abstract: A microwave heater capable of heating a bundle of wood and equipped with an optimized system for launching and/or dispersing microwave energy. The microwave launching system can include one or more split microwave launchers at least partly disposed in the interior of the heater. The microwave dispersing system can include one or more moving reflectors for rastering microwave energy emitted from the split launchers.

Abstract: A microwave heater capable of heating a bundle of wood and equipped with an optimized system for introducing microwave energy into the heater is provided. Also provided is an enhanced system for launching and dispersing within the heater. The system uses one or more TMab microwave launchers to emit microwave energy in the interior of the microwave heater in a TMab mode, where a is 0 and b is an integer between 1 and 5. The TMab launchers can be configured to emit microwave energy through an open outlet that faces generally parallel to the nearest wall of the heater. In certain situations, it can be advantageous to use at least two TMab microwave launchers having open outlets that face towards one another. In certain situations, it can be advantageous to use at least two TMab microwave launchers located on generally opposite sides of the microwave heater. In certain situations, the system can also include one or more moving reflectors for dispersing microwave energy emitted from the TMab microwave launchers.

Abstract: A commercial scale microwave system that includes a heater having enhanced heat distribution and minimized void space. The enhanced heat distribution can be provided by a unique launcher and/or reflector configuration disposed in the interior of the microwave heater. The microwave system can be operated to prevent the wood from both overheating (which results in scorching) and under-heating (which results in inadequate drying and/or inadequate thermal-modification). The microwave heating system can provide enhanced microwave energy distribution for large quantities of wood, even large quantities of wood heated under vacuum and/or in the presence of one or more chemical reagents.

Abstract: An optimized microwave barrier assembly for use in conjunction with a microwave wood heater. The barrier is configured to allow microwaves to pass therethrough in a TMab mode, where a is 0 and b is an integer between 1 and 5. The barrier assembly is also configured to maintain a pressure differential across a window of the barrier assembly. Such a configuration can reduce or eliminate arcing in the barrier assembly, even at low pressures.

Abstract: A microwave heater equipped with a microwave choke and suitable for heating wood under vacuum. The microwave choke inhibits leakage of microwave energy between a door of the heater and a main vessel body of the heater without causing arcing at the choke, even at low pressures. In certain situations, the microwave choke can be configured with side-by-side choke cavities. In certain situations, the microwave choke can be removably coupled to the door and/or vessel body for easier fabrication, installation, and/or replacement.

Abstract: An optimized system and process for heating wood using a microwave heater. The optimized system/process directs microwave energy towards different regions of the wood at different times during heating. In certain situations, microwave energy is introduced into the heater using microwave launchers and the system includes one or more microwave switches that control distribution of microwave energy to the microwave launchers so that two adjacent and/or opposing microwave launchers do not simultaneously introduce microwave energy into the heater. The optimized heating process also includes heating wood using a plurality of sequential heating cycles carried out at different conditions. For example, at least one of the heating cycles can be carried out at a lower input rate of microwave energy and/or at a lower pressure than one of the previous heating cycles.