Device and method for collecting trace sulfur trioxide in industrial gas

The invention relates to a device and a method for collecting trace sulfur trioxide in industrial gas. The device comprises a sampling tube, a constant-speed sampler, a temperature control device andan absorption bottle, and the sampling tube is an adsorption and desorption integrated sampling tube. The method is divided into an adsorption stage and a desorption stage. During adsorption, the sampling tube is put into industrial gas and heated to a certain temperature, the industrial gas is extracted by using a constant-speed sampler, and particles and sulfur trioxide in the gas are intercepted by fiber winding wires and adsorbed by an adsorption medium respectively. During desorption, nitrogen or inert gas is used for purging the sampling tube at a high temperature, and purged gas is introduced into the absorption bottle filled with a saline solution for collection and absorption. Due to the adoption of the integrated sampling tube, a sampling system is simplified, and the phenomenonof air leakage caused by e