For both crossed-flow in dense phase heat exchanger and NSP kiln, low limitation for gas speed must be noticed to prevent from or to reduce materials accumulation or collapse.
无论交叉流浓相换热器，还是传统NSP窑，必须注重低限风速的意义，防止或减少积料、塌料现象的发生；
2
Meanwhile, it was just this change that led to the quality decline of raw material and rapid collapse of Fanchang kiln in the middle North Song dynasty shortly after its establishment.
同时，这种瓷胎化学组成的变化也是导致繁昌窑北宋中期产品质量下降并最终迅速衰落的主要原因。
3
On September 5, 1944, when making charcoal in Ansai County, northern Shaanxi, he was killed by the sudden collapse of a kiln.