The vacuum operation of ceramic membranes involves the extraction of clean water through the membrane surface with minimal force.
This process promotes the formation of a plump, loosely packed filter cake that resists compression.
Contaminants in this cake are evenly distributed and their structure remains spongy, minimizing water flow resistance.
As a result, water filtered towards the membrane capillaries encounters fewer obstacles, increasing filtration efficiency.
Compared to overpressure operation, the vacuum process uses lower forces, reducing the risk of mechanical damage to the membranes.
During overpressure operation, water is forced through the membranes with great force, leading to the formation of a compact, flat filter cake.
Contaminants in this cake are compressed, increasing the resistance to water flow through the membrane.
A compact filter cake in overpressure operation generates greater friction forces, which can reduce filtration efficiency. In vacuum filtration, the loose structure of the filter cake facilitates its subsequent removal during membrane cleaning processes.
In positive pressure systems, however, dense contaminants are more difficult to remove, increasing the need for more aggressive cleaning methods.
Negative pressure allows for longer filtration cycles without the need for frequent membrane cleaning.
In positive pressure systems, membranes become clogged more quickly due to the more compact cake structure.
A loose filter cake in negative pressure creates less barriers to water flow, reducing energy consumption throughout the process.
In contrast, a filter cake in positive pressure requires more force to overcome flow resistance, leading to higher operating costs.
Ultimately, the vacuum operation of ceramic membranes provides a more efficient filtration process while reducing membrane wear and operating costs.