Plate heat exchanger is a high-efficiency heat exchanger made up of a series of metal sheets with a certain corrugated shape. The production process of sulfuric acid in the world is basically the same (the sulfur-burning sulphuric acid plant has no dilute acid purification part), and the application of plate heat exchangers in the sulfuric acid process mainly consists of three parts.
(1) The production of SO2-the source of raw materials is divided into pyrite, smelting flue gas and sulfur.
Dilute acid plate heat exchanger In the pyrite and smelting flue gas sulphuric acid process, SO2 gas is usually dirty and hot, it contains some particles, chloride ions and fluoride ions, so we need to wash and cool through the scrubber . We will use dilute acid as a washing liquid, and we need to take away the heat generated by it through a plate heat exchanger.
(2) SO2 is oxidized to SO3 in the reformer
In the case of pyrite for acid production, the drying tower is used to dry the wet SO2 gas after passing through the scrubber. In the case of sulphur-burning sulphuric acid, the drying tower is used to dry the air added to the burner. We use 93%-96% sulfuric acid as a desiccant in this station. When the water is absorbed into the acid, it will generate a lot of heat, so we need to take the heat away. This is the concentrated sulfuric acid plate heat exchanger.
(3) SO3 is absorbed by concentrated sulfuric acid in the absorption tower.
The SO3 formed in the converter is absorbed by 98.5% acid. Here we have one turn and one suction, and two turns and one suction. Usually two rotations and one suction are more common because of its better exhaust emission index. The heat generated by absorption also needs to be taken away. This is a concentrated acid plate heat exchanger.