无氨泡沫凝胶制备及其蒸发特性研究

Preparation and evaporation characteristics of ammonia-free foamed gel

为解决矿用防(灭)火材料大体积快速充填难度大、用料运输成本高和有毒有腐蚀等问题,利用含发泡剂水玻璃-无氨胶凝剂混合液与高压空气混合的快速发泡技术,制备出可实现大体积快速充填的无氨泡沫凝胶.通过比较4种促凝剂所制无氨泡沫凝胶的蒸发特性,选出成胶效果好的促凝剂D并配制出一种新型环保的无氨泡沫凝胶.研究表明,泡沫凝胶的失水率随温度升高而加快,在不同的温度下各个阶段满足不同的动力学特征;在20～120℃之间的任一恒温条件下,泡沫凝胶完全失水时间可通过方程估算出来;泡沫凝胶与凝胶的覆盖性能、物理结构的不同,使泡沫凝胶比凝胶具有更低的蒸发-失水速率.

To solve the disadvantages that ordinary mine fire extinguishing materials are toxic,corrosive and highly cost in carrying,and have difficulty in quickly filling with large volume,a kind of ammonia-free foamed gel that can be filled quickly and largely developed by applying the rapid foaming technology of mixing high-pressure air with mixture liquor containing foaming agent,sodium silicate and ammonia gelling agent is employed,and a better coagulant D is selected by comparing the evaporation characteristics of four ammonia-free foamed gels made by four coagulants.A new type of environmentally friendly foamed gel can be manufactured by utilizing coagulant D.The studies show that the water loss rate of foamed gel accelerated with increasing temperature and in various stages of different temperatures meet different dynamics characters,That the completely dehydration time at any temperature between 20℃~120℃ of foamed gel can be estimated by an equation.In addition,due to coverage characteristics and the different physical structures,foamed gel has a lower evaporation rate of water loss characteristics than gel.