Corrosion problems in the application of the hotte

Corrosion problems in the application of centrifuges

separation technology is a widely used technology, which is applicable to various industries such as medicine, chemical industry, metallurgy, textile, environmental protection, food, military and so on. It is a kind of equipment that uses centrifugal force as the driving force to separate liquid-solid, liquid-liquid or liquid-solid suspensions or emulsions according to the physical characteristics and different separation requirements to achieve different separation purposes. Because of its simple structure and high efficiency, Pure physical separation process can fully ensure the characteristics of separated materials. Therefore, centrifuges are widely used in the market

in recent years, China's national economy has been developing continuously, new technologies and processes have emerged, and the application scope of centrifuges has become more extensive; However, in this process, most manufacturers are more concerned about the separation performance and strength requirements of centrifuges, and do not pay enough attention to the impact of corrosion factors, which has brought some negative effects. This paper makes some analysis on this issue, saying that the outstanding humanized description makes the experimental operation more concise and clear for everyone to discuss

as we all know, the harm of corrosion is extremely huge. There are many examples in the world that can illustrate that centrifuges are a kind of high-speed rotating equipment, and their safety requirements are as important as pressure vessels. In the design, selection and application of most centrifuge production enterprises, they pay more attention to the impact of uniform corrosion on strength parts, and neglect the adaptability of structural design, processing technology and so on to the corrosive environment, It has led to some serious consequences. Not only the parts have corrosion tendency, but also pollute the separated materials; More serious, it even caused machine damage and human death

first, centrifuge environment

centrifugal StarTech has designed a full-automatic tensile testing machine system. The machine is divided into different types of equipment according to function and structure, but they all have common characteristics:

1, the drum is a high-speed rotating part

2. Take the drum as the main body to form the separation space

3. The drum is shaped

4. There are other connectors or accessories in the drum

these characteristics of the drum show that the core part of the centrifuge is a stress part, and its special-shaped geometry has led to the focus of this year's inspection of parts. The stress distribution of children's books and teaching aids materials is multi area, and the cooperation of multiple parts makes it possible to form a couple pair. These are some situations that deserve attention

II. Possible corrosion phenomena

metal corrosion patterns are mainly divided into two categories: uniform corrosion and local corrosion. The former is easy to find because of the apparent phenomenon, and it is relatively clear in most manual data. I will not elaborate here, but only discuss the latter

local corrosion only occurs locally, which is an extremely serious and harmful damage, such as pitting corrosion, crevice corrosion, intergranular corrosion, stress corrosion, wear corrosion, etc. in centrifuges, local corrosion is widespread, and its formation mechanism should be analyzed and measures should be taken to overcome it

1. Pitting corrosion is a highly corrosive phenomenon, which mainly exists in metals that are easy to passivate, such as stainless steel. Due to possible defects on the surface locally, there are active ions (such as halogen ions) in the solution that can destroy the passivation film, and the passivation film is locally destroyed, thus forming galvanic pairs, resulting in pitting corrosion. After the formation of pitting, due to the effect of centrifugal force, it will accelerate the dynamic process of the couple in the hole, so as to ensure the continuity of pitting corrosion until perforation, which is different from the pitting phenomenon under static state

2. Intergranular corrosion will cause parts to lose strength and extensibility, and cause brittle fracture of parts. It is a harmful damage that develops inward from the surface along the grain boundary, and there is no sign of corrosion on the outer surface. 6 End of experiment: the experiment will stop automatically after reaching the standard requirements

3. Wear and corrosion means that the surface of parts is damaged by wear and corrosion at the same time

4. Stress corrosion is the damage caused by certain tensile stress in corrosive environment. It has the following characteristics: residual tensile stress, external tensile stress, corrosive penetration environment, local defects

the above four kinds of corrosion have a very serious impact on the centrifuge, which may lead to serious consequences