Medium grade insoluble sulphur preparing process and producing apparatus

The process of preparing medium grade insoluble sulfur with industrial pure sulfur and composite stabilizer as material includes the steps of: low temperature smelting and polymerizing, passing the molten sulfur through heat insulated orifice plate and entering homogeneously and stably to specially designed quench tower to cool fast to below 60 deg.c and to become transparent elastomer, flowing out together with the coolant, and dewatering and drying to obtain medium grade insoluble sulfur. The present invention has the advantages of convenient operation, high safety and stability, low running cost, high conversion rate, etc. and is suitable for preparing insoluble sulfur with high content, high heat stability and high fineness.