超细球形空心磷铵灭火粉的制备与应用

采用气流和离心两种喷雾干燥方法制备超细球形空心磷酸二氢铵灭火粉,并添加甲基含氢硅油乳液、氟碳表面活性剂FK-510、羧甲基纤维素钠对粉体进行原位改性。结果表明:气流喷雾制备出的颗粒较细但不均匀,而离心喷雾制备出的颗粒均匀却较粗;表面活性剂甲基含氢硅油、FK-510的添加使粉体疏水性得到了很大提高;羧甲基纤维素钠的添加能使提高颗粒的球形度以及表面光滑度;喷雾干燥过程选择温度较低以及空气相对湿度较小的大气条件有利于制备高品质灭火粉。另外灭火实验结果表明:喷雾干燥制备的超细球形空心磷酸二氢铵灭火粉灭火效果明显优于某些市售灭火粉。

Preparation and Application on Superfine Spherical Hollow Ammonium Phosphate Fire-extinguishing Powder

The superfine spherical fire-extinguishing powder, ammonium dihydrogen phosphate(NH4H2PO4), was prepared using air-blast spray drying and centrifugal spray drying respectively, and modified in situ with methylhydrosiloxane emulsion, fluorocarbon surfactant FK-510 and sodium carboxymethyl cellulose(CMC). The results indicated that the particles prepared by air-blast spray drying were finer than those prepared by centrifugal spray drying, but less uniform. The addition of methylhydrosiloxane and FK-510 improved particle hydrophobicity and brought fine dispersion, and CMC made the particles more smooth and spherical. The low air temperature and low air relative humidity should be chosen during the drying process. In addition, the fire experiment indicated that the effect of superfine spherical fire-extinguishing powder prepared by spray drying was much superior than some other powders on sale.