Porous Ceramics for Fluidized Bed
Refractron Technologies Corp. is a leading manufacturer of technical ceramics. Products include both controlled porosity and densely structured ceramics designed to meet requirements specified by our customers for durability, chemical, corrosion and wear resistance, toughness, and density.
Refractron porous ceramics are used for applications that require flowing air through a porous plate to keep powdered materials fluidized to facilitate a chemical process or move the material in the process. The precisely controlled porosity and pore size of porous ceramic is excellent for this as is allows components to be custom tailored to the application requirements.
The range of Refractron porous ceramics are made by fusing aluminum oxide grains using porcelain bond to for a strong, uniformly porous and homogeneous structure. Refractron's porous ceramic has 40-50% open porosity and is available in pore sizes ranging from 6 to 90 microns. Monolithic, single grade, aluminum oxide porous ceramic is available in 6, 15, 30, 50, 60 and 90 micron pore sizes.
Aluminum oxide is the standard material and has a maximum operating temperature of 1400 F (800 C). Porous ceramics are resistant to solvents and have good acid resistance with the exception of hydrochloric and phosphoric acids. The advantages of porous ceramics are that they are not only mechanically strong but inert and can be cleaned and reused in many process applications. Porous ceramic is used in tough applications to replace porous metal or as an alternative to plastic or fabric media.
Porous ceramic is cleaned and reused using a variety of methods depending on the contaminant to be removed. Specifically tailored techniques include:
- Oven firing
- Dilute acid cleaning
- Solvent cleaning
- Steam and ultrasonic cleaning
The range of porous ceramics includes discs (from 2" to 20" diameter), plates (up to 12" square) and other custom shapes and components made from aluminum oxide where tightly controlled pore size and porosity is critical. Common parts for porous ceramics include:
- Ash handling plates
- Fluidized bed plates
- Pneumatic conveying plates
Other specialty products include a range of adsorbent filter/drier cores for refrigeration applications, filters, diffusers, vacuum chucks, wicks and gas probes.
Porous ceramics are readily machinable using conventional diamond cutters and wheels. Since it is not ductile and the granules are removed the porous ceramic pore structure is not affected by cutting and grinding. Typical diamond tile saws are routinely used to cut porous ceramic tubes and test coupons.