Centrifuge separation technology is an extremely widely used technology for pharmaceutical, chemical, metallurgy, textile, environmental protection, food, military and other industries. It is driven by centrifugal force and will be liquid-solid, liquid-liquid. Or a liquid-liquid-solid suspension or emulsion according to the physical characteristics, separation requirements to achieve a different separation of the purpose of a device, due to its simple structure, high efficiency, pure physical separation process, can fully guarantee separation The characteristics of the material. Therefore, the market for centrifuges is extremely extensive.
In recent years, China's national economy has continued to develop, new technologies and new processes have emerged, and the scope of application of centrifuges is more extensive. However, in this process, most manufacturers are more concerned about the separation performance and strength of centrifuges. Requirements, the impact of corrosion factors are often not enough, which brings some negative effects. This article makes some analysis and explanation for this issue for everyone to explore.
As we all know, the danger of corrosion is extremely huge. There are many examples in the world that the centrifuge is a high-speed rotating equipment, and its safety requirements are as important as pressure vessels. Most centrifuge manufacturers are designing, selecting and In the application, more attention is paid to the influence of uniform corrosion on strength parts, neglecting the adaptability of structural design and processing technology to corrosive environment, resulting in some serious consequences. Not only the parts tend to corrode, but also the materials that are separated from the pollution; even more serious, even the machine is destroyed.
First, the centrifuge environment
Centrifuges are divided into different types of equipment according to their functions and structures, but all have common characteristics:
1. The drum is a high speed rotating part;
2. The separation space is formed by the drum as the main body;
3. The rotating drum has a special-shaped structure;
4. There are other couplings or accessories in the drum.
These characteristics of the drum indicate that the core part of the centrifuge is a stress member, and its profiled geometry results in multiple stress distribution of the part, the cooperation of multiple parts, and the possibility of forming a pair of galvanic couples. These are some of the things that are worth noting.
Second, possible corrosion phenomena
Metal corrosion forms 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 clearly expressed in most manual data. It will not be described in detail here, and only the latter will be discussed.
Localized 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 should be Focus on the analysis of its formation mechanism and take measures to overcome it.
1. Pitting corrosion is a highly corrosive phenomenon, mainly in easily passivated metals, such as stainless steel. Due to possible local defects in the surface, there are active ions in the solution that can destroy the passivation film (such as halogen Ion), the passivation film is partially destroyed, thereby forming a pair of galvanic couples, causing pitting corrosion. After the pitting corrosion is formed, due to the centrifugal force, the dynamic process of the galvanic couple in the hole will be accelerated, thereby ensuring the continuity of the hole corrosion until the perforation, which is different from the pitting phenomenon under static.
2. Intergranular corrosion will cause the parts to lose strength and extensibility, causing the parts to be brittle. It is a kind of harmful damage that develops from the surface along the grain boundary and has no signs of corrosion on the outer surface.
3. Wear and corrosion means that the surface of the part is subject to both wear and corrosion damage.
4. Stress corrosion is damage caused by a certain tensile stress in a corrosive environment. It has the following characteristics: residual tensile stress, applied tensile stress, corrosive infiltration environment, local defects.
The above four types of corrosion are extremely severely affected by the centrifuge and may cause serious consequences. More information on
Office Safe,Office Safe Box,Office Safety Box,Office Security Box
Ningbo Zhaomu Electronic Commerce Co., Ltd. , https://www.bofonhome.com