Heater, use thereof and method for preparing isocyanate using heater

A heater for heating and vaporizing droplets in a gas stream, comprising a heater housing and a heater body located inside the heater housing, the heater housing is provided with an airflow inlet, a drain port and an airflow outlet, wherein the airflow inlet is provided on the side wall of the heater housing, the airflow outlet is provided on the top of the heater housing, and the drain port is provided at the bottom of the heater housing;

• an airflow enters into the heater housing via the airflow inlet, flows through the heater body, and then is discharged via the airflow outlet;
• the heater body consists of one or more stereoscopic network structures formed by interweaving one or more electrical heating wires and is in form of a cylinder shape with a height-to-diameter ratio of the heater body is 1:1-10;
• wherein, a cross section of the electrical heating wire is in a shape of an arch;
• wherein, a central angle corresponding to an arc of the arch is 1°-10°;
• and
• wherein, the gas stream is an amine gas stream, and the droplets are amine droplets.