—— Steel pickling heater drawings ——
Steel pickling heater It is commonly used for pickling of oxide film of steel materials such as steel pipe pickling, steel wire pickling and steel strip pickling, and is a heating equipment that needs to be configured in most pickling. Pickling is to make iron and steel have a clean and active surface, to ensure the surface quality of the produced steel, and to remove iron scale and rust on the surface by warm pickling. Hydrochloric acid or sulfuric acid is generally used for steel pickling, and nitric acid and hydrofluoric acid are mostly used for stainless steel.
Hydrochloric acid, sulfuric acid and hydrofluoric acid are extremely corrosive. In the pickling process, in order to improve the pickling efficiency, it is usually necessary to heat the acid solution. In the past, many factories, especially steel strip production enterprises, did not have suitable heat exchange equipment capable of resisting hydrochloric acid corrosion, so the acid liquid was heated by steam direct flushing. Although the pickling solution temperature can be raised to the process temperature in this way, many other problems are brought about. For example, direct flushing leads to a large amount of acid mist, which dilutes the concentration of acid solution, reduces the cleaning efficiency of acid solution and causes acid waste.
There are generally two kinds of iron scale on the surface of steel: one is rust, which is an oxide generated by SO2 and CO2 dissolved in water and catalyzed in humid environment at normal temperature. This rust layer is reddish brown and is composed of bivalent and trivalent iron and oxygen compounds and crystal water; The other is oxide iron sheet produced at high temperature, commonly known as iron scale, which is dark black or dark brown. It is formed under two conditions: one is rolled iron sheet formed during rolling or welding, and the other is iron oxide sheet formed during heat treatment because the oxygen partial pressure is greater than the equilibrium oxygen partial pressure of iron. In the production of hot-dip galvanized, galvanized, coated or plastic-coated steel pipes, even if very thin iron sheets exist, it is impossible to coat a complete and continuous zinc layer. If the surface oxide is not removed during coating or cladding treatment, it will cause bubbling and reduce the corrosion resistance of the coating.
Iron and steel pickling heating equipment is made of fluoroplastic material. Immersion pickling heater or shell-and-tube pickling heater can be selected. Users can choose according to the actual situation in production.
Steel pickling heater is a non-standard customized product. Users provide working conditions and technical parameters, and technicians calculate product parameters such as product structure, product shape, fluoroplastic number, length and inlet and outlet pipe diameter before selecting pickling heating equipment.