| 摘要 |
<p>The invention relates to a filter tube and a method for making the filter tube. The filter tube consists of a plurality of randomly disposed interrelated inorganic fibers having a diameter of from about 0.001 to 10 microns. The tube forms a semirigid, self-supporting, porous, filter tube of desired filtering porosity and efficiency, and the fibers of the filter are bonded at the junction of the fiber crossover points with a bonding amount of a substantially nonhydroscopic pyrolyzed quaternary ammonium silicate as a binding agent. The filter tube of the invention is characterized by a high collapse strength and substantially nondusting properties during handling. The method for making the tube consists of impregnating a filter tube composed of interrelated, nonwoven negatively charged inorganic glass fibers, having a diameter from about 0.001 to 10 micorns, with a liquid dispersion of positively charged particles of a nitrogen substitute silicate compound. The impregnated filter tube is then heated to a temperature of about 800 to 1100.degree.F to provide an inorganic pyrolyzed silica binder, thereby forming a self-supporting porous filter tube subject tot use at high temperature.</p> |
