Gas-solid separating method and system for simple substance sulphur in sulphur-containing exhaust

A gas-solid separating method for simple substance sulphur in sulphur-containing exhaust, comprising the following steps:

• a) cooling the sulphur-containing exhaust comprising simple substance sulphur vapor and dust particles to a temperature below 25° C. so that the simple substance sulphur vapor in the sulphur-containing exhaust is condensed into simple substance sulphur solid particles, and the simple substance sulphur solid particles and the dust particles are settled to an extraction tank to produce a first exhaust;
• b) washing the first exhaust with first washing liquid to produce second exhaust and second washing liquid, wherein the first washing liquid is a first heavy liquid phase solvent, the second exhaust is discharged, the second washing liquid flows into the extraction tank and is layered into a light liquid phase solvent and a second heavy liquid phase solvent, the dust particles are dissolved in the light liquid phase solvent in the extraction tank, the light liquid phase solvent is discharged, and the simple substance sulphur particles are dissolved in the second heavy liquid phase solvent in the extraction tank;
• c) extracting the second heavy liquid phase solvent, heating the extraction tank to 50-90° C. by irradiation, collecting the simple substance sulphur particles, and evaporating to produce a heavy gas phase solvent;
• d) cooling the heavy gas phase solvent to a temperature below 25° C. so that the heavy gas phase solvent is converted into the first heavy liquid phase solvent, the first heavy liquid phase solvent is extracted and returned to step 1, and the first washing liquid consumed for washing the first exhaust is replenished.