Dismounting-and-washing-free descaling method for dilute acid plate heat exchanger

The invention discloses a dismounting-and-washing-free descaling method for a dilute acid plate heat exchanger. The dilute acid plate heat exchanger is adjusted once after normally working for two months, specifically, a hot dilute sulphuric acid inlet and a cold circulating process water inlet of the dilute acid plate heat exchanger are exchanged, and meanwhile a hot dilute sulphuric acid outlet and a cold circulating process water outlet are exchanged, so that cold circulating process water is fed into a flow channel where hot dilute sulphuric acid is fed originally, and hot dilute sulphuric acid is fed into a flow channel where cold circulating process water is fed originally; and after the dilute acid plate heat exchanger works for four work hours after the exchange, the hot dilute sulphuric acid inlet and outlet and the cold circulating process water inlet and outlet are exchanged correspondingly to recover the original state. According to the method, operation is simple, consumed time is short, the heat exchange efficiency of the heat exchanger is ensured, and normal production is not influenced. According to the method, the link of dismounting and washing plates is omitted, damage to rubber sealing strips and the complex procedure for pasting the rubber strips again are avoided, corresponding material cost is omitted, labor input is reduced, and cessation of production is not needed. Compared with conventional methods, the method can prolong the service life of equipment by three to five years.