How to Anti the Corrosive of the Separation Equipment
How to Anti the Corrosive of the Separation Equipment
Centrifuge is of simple structure,easy operation, and each operation can be adjusted, residues can be washed, the solid particles are not easy to break, good adpatability, Widely used in chemical industry, light industry, textile,doof,pharmaceutical,metallurgy, mining,each and environmental protection industries.In the separation case, always be the liquid-solid type, liquid-liquid type and liquid-liquid-solid type.Therefore, the centrifuge application is widely used in the present industrial market.
In recent years, our country national economy sustainable development, is an emerging new technology and new technology, the application range of the centrifuge is also more widely; In this process, however, most of the manufacturer is more concerned about the centrifuge separation performance, strength requirements, the corrosion factors not often enough attention, which has brought some negative effects, this paper analyzed some problems with this specification, for everybody to discuss.
As is known to all, the harm of corrosion is very large, there are many examples in the world can explain, centrifuge is a kind of high speed rotating equipment, its safety requirements and pressure vessels are equally important, most of the centrifuge manufacturing enterprise in design, selection and application, and more about the uniform corrosion influence on strength of parts, neglect the structure design and processing technology of the corrosion environment adaptability, such as led to some serious consequences. Parts not only a tendency toward corrosion, pollution is separated material; Is more serious and even cause the machine apart.
The centrifuge environment
Centrifuge according to the function and structure are divided into different types of equipment, but all have a common characteristic:
1, for high-speed rotating drum;
2, form with the drum separation space;
3, drum of special-shaped structure;
4, drum and other connecting parts or fittings.
These a few characteristics of drum, illustrates the centrifuge is a stress core parts, its special geometry, led to the parts of the stress distribution in many areas, many parts, and made it possible to form a galvanic couple of opportunity, it is worth noting.
The possible corrosion phenomena
Metal corrosion morphology mainly divided into two major categories of uniform corrosion and local corrosion, the former because the apparent phenomenon is easy to find, and is expressed in most of the manual data is clear, in this not elaborate, just as some discussions on the latter.
Local corrosion occurs only in local, is an extremely serious, harm the destruction of a large, such as pitting corrosion, crevice corrosion, intergranular corrosion, stress corrosion and wear corrosion, etc., in the centrifuge, local corrosion is widespread, and should be analyzed from the aspects of its formation mechanism, take measures to overcome them.
1.pitting corrosion is a highly corrosion phenomenon, mainly exist in the passivation of the metal, such as stainless steel, because of the possibility of partial surface defect, and exist in the solution can destroy passivation film of reactive ion (e.g., halogen ions), passivation film is destroyed by the local, to form a galvanic couple, cause pitting corrosion. Pitting corrosion after forming, due to the effect of centrifugal force, will speed up the dynamic process of hole galvanic so as to ensure the sustainability of hole corrosion, perforation, this is different from under the static of pitting corrosion phenomenon.
2.intergranular corrosion can cause parts lose strength and extensibility, cause parts brittle fracture, it is a kind of from the surface along the grain boundary to the development of the dangers of outside surface shows no sign of corrosion damage.
3 .corrosion, wear and tear parts namely surface wear and corrosion damage at the same time.
4.stress corrosion in the corrosive environment, due to the certain tension stress effect and cause damage. It has the following characteristics: residual tensile stress and gallas stress, corrosive environment, local defects.
