Abstract
The unconfined two-dimensional expression of semisolid material in a tube-type press, where the material is compressed on a cylindrical filter element, is investigated under constantpressure conditions. An equation for analysing the expression rate is presented by introducing a newly defined value of effective consolidation area factor jII. To evaluate the area factor jII for constant-pressure expression of homogeneous semisolid material, the basic consolidation equation based on the Terzaghi's model is solved, and a simplified equation is derived in terms of the ratio (Do/Di) of the outer to the inner diameter of the original material. It is demonstrated that the area factor jII can be calculated with sufficient accuracy to adequately estimate two-dimensional expression processes. A logical method for predicting the dehydration in a tubular press is shown, in consideration of the fact that the deliquoring rates of two-dimensional expression are larger than those of conventional one-dimensional expression by the factor (jIIII2-1).
Satisfactory agreement between theory and experiments is assured under the conditions of technical interest, where the ratio (Do/Di) ranges up to 2.0.
