| 摘要 |
The process is based on abrupt discharge of air through the diffuser forming an expansion wave which brings about compaction of sand housed in a moulding box. This takes place with free escape of air, for which purpose the residual air escape pipe, pref. situated axially on the discharged air storage bell, opposite the moulding box, is kept open, either by opening the appropriate valve, or by absence of such valve. In this way, at the end of the almost instantaneous compaction, no residual pressure exists in the diffuser, nor is there the usual counter-current of air to eliminate this residual pressure. (0/2)
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