Methods of containing fluids deleterious to the container

A method of temporarily containing a hot fluid in a chamber defined at least in part by a permeable wall member, the hot fluid having a temperature at least equal to the minimum deterioration temperature of the wall member, the hot fluid thereby having a deleterious effect on the wall member on contact therewith;

• which comprises;
• providing for the chamber at least one wall member constructed of heat insulating, refractory ceramic fibers comprising fibers of inorganic compounds selected from the group consisting of alumina, silica, zirconia and silica/alumina, the wall member having a density of from 0.16 to 0.80 g/cm.sup.3 and a uniform permeability, to an auxiliary fluid having no deleterious effect on said wall member, of from 10.sup.-5 to 10.sup.-9 cm.sup.2 ;
• causing said auxiliary fluid to permeate through the permeable wall member, under a pressure from outside the chamber and pass into the chamber, said auxiliary fluid having a temperature below the minimum deterioration temperature of the wall member and being non-deleterious toward the wall member and the fluid to be contained;
• introducing the fluid having a deleterious effect on the wall into the chamber under a pressure less than the pressure of the auxiliary fluid;
• and removing the fluid having a deleterious effect from the chamber;
• whereby the passage of the auxiliary fluid reduces the contact between the deleterious fluid and the wall member during the residence time of the deleterious fluid in said chamber.