ABSTRACT In this study, the possible reason for conveying problems sometimes observed in the pneumatic transport of casting powders from the storage containers to the mould was studied. Since some correlation in the occurrence of the said conveying problems to days with high humidity has been observed, the influence of the relative humidity of the air on the flowability of casting powders was investigated. The results showed that below a relative humidity of approximately 75%, all three casting powders investigated were free-flowing but with increasing humidity, the flowability decreased. At a relative humidity of 90%, only one casting powder was cohesive but not very cohesive. To avoid problems in pneumatic conveying, therefore, the relative humidity of the atmosphere in the pneumatic conveying system and the storage bins has to be limited.

中文翻译：

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铸粉：湿度对流动性的影响

摘要 在这项研究中，研究了铸造粉末从储存容器到模具的气动输送过程中有时观察到的输送问题的可能原因。由于已经观察到所述输送问题的发生与高湿度天存在一些相关性，因此研究了空气的相对湿度对铸粉流动性的影响。结果表明，在大约 75% 的相对湿度以下，所研究的所有三种铸造粉末都是自由流动的，但随着湿度的增加，流动性下降。在 90% 的相对湿度下，只有一种铸粉具有内聚力，但内聚力不是很强。因此，为了避免气力输送出现问题，必须限制气力输送系统和储料仓中大气的相对湿度。