Methods are disclosed in which two or more forming chambers are used to process inorganic fibers by gravity-laying methods.

All embodiments of the process next employ gravity settling the specimen in a near horizontal oriented container (21, 121, 221).

Water can be withdrawn from the digested sludge in the fermentation tank by using, for example, a mechanical concentration device, a gravity-settling tank, or a filter attached to the inner face of the fermentation tank.

Sedimentation is a physical wastewater treatment process used to settle out suspended solids in water under the influence of gravity.