Choosing the Right Titanium Fiber Sintered Felt for Filter Systems
To select the appropriate sintered titanium fiber felt for your filter system, consider the following factors:
1. Filter Material Composition: Avoid filter materials with high colloidal substance content. Titanium fiber felt is recommended for filtering rigid solid particles effectively.
2. Backwashing Pressure: Pay attention to the pressure used for backwashing the titanium fiber sintered felt. It should be controlled within 0.3MPa to ensure easier regeneration.
3. Limitations of Titanium Fiber Sintered Felt: Keep in mind that sintered titanium fiber felt can only separate solid and liquid and remove mechanical particles. It is not effective in removing various metal ions.
4. Chloride Ion Concentration: Choose a filter material with low chloride ion concentration to prevent potential issues.
5. Precision Selection: Select an appropriate titanium fiber sintered felt with a diameter significantly smaller than the solid impurities to prevent their entry into the inner pores of the filter wall.
6. Regeneration Methods: Different impurities require different regeneration methods. Consider options such as air or steam backflushing, backwashing, positive washing, acid washing, alkali washing, and ultrasonic cleaning.
Stages of Titanium Fiber Sintered Felt Production
1. Low-Temperature Burn-in Stage: This stage involves the recovery of metal, volatilization of adsorbed gas and moisture, and decomposition and removal of the forming agent in the compact.
2. Medium-Temperature Heating and Sintering Stage: Recrystallization occurs during this stage. Deformed grains within the particles are recovered and reorganized into new grains. Additionally, oxides on the surface are reduced, and sintering necks form at the grain interface.
3. High-Temperature Heat Preservation to Complete Sintering Stage: In this stage, diffusion and flow processes are fully carried out and nearly completed. Closed pores are formed, shrinking the pore size and total number of pores, significantly increasing the density of the sintered body.
Filtration Processes with Stainless Steel Fiber Sintered Felts
First Stage (Stable Stage): During the initial stages of filtration, the fluid passes through the pores of the stainless steel fiber sintered felt, and various filtration mechanisms occur. Contaminating particles mix with the fluid, rapidly filling individual channels and accumulating on the inner pores' surface or the filter material's surface. The flow is primarily along the normal direction, and the resistance of the filter material remains stable.
Second Stage (Unstable Stage): As the pores of the filter material narrow or become blocked, contaminated particles accumulate on the surface, forming a filter cake and a new filter layer. Filtration occurs through both the filter cake and the filter media, resulting in increased resistance and higher filtration efficiency.
Sintering Methods for Stainless Steel Sintered Felts
1. Normal Pressure Sintering Method: Sintering is carried out under normal atmospheric pressure and atmosphere conditions, at the required temperature and time.
2. Hot Pressing Method: Powder filled in the mold is heated while being pressurized, often using high-frequency induction heating. This method produces sintered materials with high strength and good compactness.
3. High-Temperature Isostatic Pressing Method: This method applies isotropic pressure to sinter the material at a very low temperature, allowing materials that cannot be sintered under normal pressure to be processed. Although it yields excellent performance, the equipment and operating costs are expensive.
Reasons for Frequent Replacement of Stainless Steel Pleated Sintered Felt Filter Elements
1. Unstable Raw Water Quality: Fluctuations in the quality of raw water lead to excessive particulate matter entering the filter element, shortening its lifespan.
2. Poor Pretreatment Operation: Incompatibility or mismatch between flocculants, antiscalants, and the water source used for pretreatment can result in sticky substances adhering to the filter element's surface, reducing its effective filter area and necessitating frequent replacements.
3. Filter Element Quality: Poor-quality filter elements have similar inner and outer pore diameters, limiting their filtration efficiency. High-quality filter elements have gradually reducing pore sizes from the outside to the inside, allowing for longer periods of effective filtration.
Proper maintenance is essential to prolonging the life of stainless steel pleated sintered felt filter elements.
