Experiments in pneumatic conveying show that there exists a maximum particle concentration.
气力输送实验表明，这里存着一个最大的颗粒浓度。
2
By using the capacitance tomography, tested and studied was the concentration of solid conveyed by a dilute-phase pneumatic force at a normal temperature.
采用电容层析成像技术，对常温下稀相气力输送的固体浓度进行了测试研究。
3
The concentration and size of pulverized coal in pneumatic transportation pipe in power station are of great influence on the efficient, emission and operating safety.