Microwave device and flow tube used therein

A microwave device, comprising:

• a microwave generator configured to generate a microwave and output the microwave;
• a waveguide configured to guide the microwave output from the microwave generator;
• a cavity resonator having an irradiation chamber which is a cylindrical cavity,
• the microwave generator and the cavity resonator being configured to:
• introduce the microwave guided by the waveguide into the cylindrical cavity,
• excite an electric field by resonating the microwave in the irradiation chamber, and
• generate the electric field in TM010 mode along a direction of a center axis through centers of top and bottom faces of the irradiation chamber, such that the center axis is a location where the electric field is the strongest in the irradiation chamber;
• and
• a flow tube installed in the irradiation chamber, formed in a helical fashion by winding and extending around the center axis, and configured to cause a liquid to be treated to flow in a direction crossing the electric field generated in the irradiation chamber,
• wherein a winding diameter d1 of the flow tube is equal to or less than 50% of a diameter of the bottom face of the cylindrical cavity.