Filtration equipment first appeared during the European Industrial Revolution in the 19th century. The earliest industrial filtration equipment that came out were filter presses, leaf filters and spiral filters.
Spiral filter, also known as screw extrusion dehydrator, first appeared in Germany in the 1960s, and then the former Soviet Union, Sweden, the United States and other countries have successively manufactured this kind of filter, and it was first used in oil extraction and fish grinding. In recent years, it has been widely used in the field of sludge dehydration and other industrial process dehydration in the field of crushed meat dewatering, fish and shrimp waste filtration.
In the early days, the screw filter discovered such a situation when filtering waste materials such as fish and shrimp. At the beginning of the filtration, the feed was squeezed and the filtrate flowed out of the filter. But after filtering for a period of time, the filtrate stops flowing, and the filter cake will not be discharged from the discharge port. The main reason is that the material concentration increases, and the filter efficiency is reduced due to the filter mesh structure, which causes clogging.
With the development of spiral filtration technology, in order to avoid the problem of clogging, a relatively new type of filter structure, such as a grid filter structure and a fixed ring filter structure, appeared in Germany and other European countries in the 1970s. Among them, the dynamic and fixed ring structure filter screen is covered with multiple ring pieces on the spiral shaft. The ring pieces are divided into two types: fixed ring pieces and movable ring pieces. The fixed ring and the movable ring are separated from each other and have a certain filtering gap. Through the friction of the material between the movable ring and the fixed ring, the friction force that promotes the extrusion of the material is greater than the hindrance, thereby improving the filtering and separating effect of the material and avoiding Blocking of high-viscosity materials.
For example, the moving and stationary ring filter structure spiral filter equipment produced by Darmstadt University of Technology in Germany, FAN Company and LYCO Company in the United States suitable for fishery, farms and other fields-the prototype of the stacked screw sludge dewatering machine has been launched. It can well avoid the problems caused by congestion, and because of this, it has been promoted in countries such as Japan and South Korea where the fishery and food industries are developed.
In recent years, the stacked screw sludge dewatering machine has also been developed, innovated and promoted in my country. Due to the easy separation and non-clogging characteristics of the stacked screw sludge dewatering machine, it has been widely used in municipal sewage treatment and industrial wastewater treatment. Petrochemical, pharmaceutical, textile, metallurgy, food and beverage, mining and many other fields.
With the development of various new materials and control technologies, some domestic companies have also made some innovations and improvements on the basis, such as improvements to screw shafts, wear-free structures, and industry-specific models.