剪切条件下中浓纸浆的流动特性和能量耗散(英文)

Flow Properties and Energy Dissipation of Medium-Consistency Pulp in Shear Condition

对中浓纸浆悬浮液在剪切室内的流动特性和能量耗散进行了研究.结果表明:中浓纸浆悬浮液在高剪切应力下可以达到流体化状态,此时其流动特性与水类似;根据中浓纸浆在流体化过程中的温度变化可以计算其能量耗散值;由于中浓纸浆中纤维之间存在着较大的摩擦力,因此耗散的能量与输入能量的比值很高,这对于中浓纸浆的泵送是很不利的;当中浓纸浆质量分数为13.2%时,其在流体化状态下的能量耗散值为498.96 kW/m3,表观粘度为7.94Pa.s,所耗散的能量占输入能量的45.62%,且随着纸浆质量分数的升高而增大.

This paper studies the flow properties and energy dissipation of medium-consistency （MC） pulp suspension in rotary device. The results indicate that （ 1 ） MC pulp suspension is of similar flow properties to water when it displays fluid-like behavior （fluidization） in rotary device under high shear stress ; （2） the energy dissipation of MC pulp suspension can be estimated by the temperature change during the fluidization ; （ 3 ） because of the large friction among fibres, the energy dissipation occupies a high ratio to the input energy during the fluidization, being disadvantageous to the pumping of MC pulp suspension; and （4） the apparent viscosity of the pulp suspension with a mass fraction of 13.2% is 7.94 Pa · s, and the corresponding energy dissipation is 498.96 kW/m^3 , which is 45.62% of the input energy and increases with the mass fraction of the suspension.