Examination of Gas Flows in Cores About the Changeable Cross-sections Executed in the Cold-box Technology

The measurement results of the gas pressure in intergranular spaces of fast-setting moulding sands, hardened by a reactive gaseous factor, are presented in the hereby paper. In addition, the new research stand for measuring gas pressure changes in the core of a variable cross-section, during hardening of this core, is shown. The measuring method is also described. Investigations concern determinations and recording of the gas pressure pathways in moulding sands along the core height, in five measuring points. The influence of the hardening gas pressure on the gas distribution in the moulding sand was determined. The influence of the shape change (cross-section) of the core on the character of changes of the hardening gas pressure in the core being hardened, was also shown. The hardening gas of a constant pressure was fed continuously into the core.