On the design of solid-liquid separation cyclones

The particle size is relatively small, so centrifuges are not suitable, nor are cyclones. Cyclones are appropriate for situations where the flow rate is high but the requirements for grading are not strict. In the owner’s case, a plate and frame filter press would be a better choice. Plate and frame filter presses can handle a wide range of materials for solid-liquid separation, and it’s easy to adjust the particle size for grading as well as the filtering precision. Although it requires more manual labor, it operates in a continuous, automated manner, and most importantly, it meets the separation requirements in this situation.

I don’t think what was said on the second floor is quite correct. Under my supervisor’s guidance, I have mainly focused on research related to cyclones and cyclone separators, and the separation accuracy of these separators is quite high. With older cut-in type cyclones, the efficiency in separating sand particles larger than 10 microns can reach 80%–90%. Of course, this also has a lot to do with the density and viscosity of the solid. The flow rate for 6 sides should be sufficient with a diameter of 150 MM.

2# chinazwr: The by-product salt requires a water content of 3-5%; plate and frame filter presses are not suitable for this purpose, nor are they useful in the calcium chloride industry. Still, thank you

3# wjian17 I’m very grateful for your participation. What flow rate is required to achieve the separation effect you mentioned? Please feel free to give your advice

I agree with what Mr. Hai Chuan said; centrifuges are not suitable, while plate and frame filter presses should work. It’s not clear exactly how fine the particles in the material used by the poster are; plate and frame filter presses utilize high-precision filter cloths, and it is entirely possible to retain particles with a size of 0.1 um.

If the particle size of the by-product calcium chloride is small and it is difficult to separate it using a centrifuge, it is also hard to separate it with a solid-liquid separation cyclone. Previously, I was involved in a project dealing with the separation of sodium carbonate particles, whose particle sizes ranged from 0.50 micrometers to 10 micrometers; it was difficult to handle this issue even using continuous centrifuges. If an intermittent centrifuge is used, it is limited by the processing capacity and labor intensity. In the end, a \"precision filter\" was chosen for separation, with a solid powder sintered filter element as the filtering medium. The processing capacity is 15 tons/h, with a solid content of around 5%. If the original poster has any further questions, they can call “*aoqiang-39@163.com"

When using sintered tubes for filtration, the biggest problem is that the filter elements often get clogged, and after a certain period of time, the backwashing effect becomes ineffective.

Looking at everyone’s responses, I feel it’s necessary to explain in more detail. During the concentration of calcium chloride solution, sodium chloride (table salt) precipitates out. The centrifuges used in this industry are generally cone basket or reciprocating type centrifuges; they use filter screens instead of filter cloths. These centrifuges can handle large volumes of material and operate in a rather rough manner. By “fine crystalline salts,” I mean that the crystals are relatively fine, but they don’t reach the micron level. Normal crystals should fall within the range of 40 to 100 mesh. If the particle size exceeds 100 mesh, there will be too many such particles, and the solid-liquid ratio will be insufficient, which affects the separation efficiency. In these types of centrifuges, filtration is achieved through high-speed rotation that creates a filter cake layer; then, centrifugal force or push rods are used to discharge the material automatically. If no large-sized particles are formed, no filter cake layer can be created, and thus even small-sized particles cannot be filtered out.

Can this type of cyclone filter be made corrosion- and explosion-resistant? Can chemically organic strongly acidic suspensions be separated?

Hello, based on the experience of units such as Qingdao Alkali Plant and Lianyungang Alkali Plant, calcium chloride in the form of small particle crystals can be treated using LLW450 at a rate of 6 T/h. Of course, with a solid content of 24%, it would be beneficial to use a cyclone before the centrifuge to concentrate the material!